1.9 How do you pronounce Ethereal? Where did the name come from?
+ 1.10 Does Ethereal work on Windows Me?
+
+ 1.11 Does Ethereal work on Windows XP?
+
2. Downloading Ethereal:
- 2.1 I downloaded the Win32 installer, but when I try to run it, I get an
- error.
+ 2.1 Why do I get an error when I try to run the Win32 installer?
- 2.2 When I try to download the WinPcap driver and library, I can't get to
- the WinPcap Web site.
+ 2.2 Why can't I get to the WinPcap Web site in order to download WinPcap?
3. Installing Ethereal:
- 3.1 I installed an Ethereal RPM, but Ethereal doesn't seem to be installed;
- only Tethereal is installed.
+ 3.1 I installed an Ethereal RPM; why did it install Tethereal but not
+ Ethereal?
4. Building Ethereal:
- 4.1 The configure script can't find pcap.h or bpf.h, but I have libpcap
- installed.
+ 4.1 I have libpcap installed; why did the configure script not find pcap.h
+ or bpf.h?
4.2 Why do I get the error
when I try to build Ethereal from SVN or a SVN snapshot?
- 4.3 The link fails with a number of "Output line too long." messages
- followed by linker errors.
+ 4.3 Why does the linker fail with a number of "Output line too long."
+ messages followed by linker errors when I try to buil Ethereal?
- 4.4 The link fails on Solaris because plugin_list is undefined.
+ 4.4 When I try to build Ethereal on Solaris, why does the link fail
+ complaining that plugin_list is undefined?
- 4.5 The build fails on Windows because of conflicts between winsock.h and
- winsock2.h.
+ 4.5 When I try to build Ethereal on Windows, why does the build fail because
+ of conflicts between winsock.h and winsock2.h?
-5. Using Ethereal:
+5. Starting Ethereal:
- 5.1 When I use Ethereal to capture packets, I see only packets to and from
- my machine, or I'm not seeing all the traffic I'm expecting to see from or
- to the machine I'm trying to monitor.
+ 5.1 Why does Ethereal crash with a Bus Error when I try to run it on Solaris
+ 8?
- 5.2 I can't see any TCP packets other than packets to and from my machine,
- even though another analyzer on the network sees those packets.
+ 5.2 When I run Tethereal with the "-x" option, why does it crash with an
+ error
- 5.3 I'm only seeing ARP packets when I try to capture traffic.
+ "** ERROR **: file print.c: line 691 (print_line): should not be reached.
- 5.4 I'm running Ethereal on Windows; why does some network interface on my
- machine not show up in the list of interfaces in the "Interface:" field in
- the dialog box popped up by "Capture->Start", and/or why does Ethereal give
- me an error if I try to capture on that interface?
+ 5.3 When I run Ethereal on Windows NT, why does it die with a Dr. Watson
+ error, reporting an "Integer division by zero" exception, when I start it?
- 5.5 I'm running Ethereal on Windows; why do no network interfaces show up in
- the list of interfaces in the "Interface:" field in the dialog box popped up
- by "Capture->Start"?
+ 5.4 When I try to run Ethereal, why does it complain about
+ sprint_realloc_objid being undefined?
- 5.6 I'm running Ethereal on Windows; why doesn't my serial port/ADSL
- modem/ISDN modem show up in the list of interfaces in the "Interface:" field
- in the dialog box popped up by "Capture->Start"?
+ 5.5 When I try to run Ethereal on Windows, why does it fail to run with a
+ complaint that it can't find packet.dll?
- 5.7 I'm running Ethereal on a UNIX-flavored OS; why does some network
- interface on my machine not show up in the list of interfaces in the
- "Interface:" field in the dialog box popped up by "Capture->Start", and/or
- why does Ethereal give me an error if I try to capture on that interface?
+ 5.6 Why do I get the error
- 5.8 I'm running Ethereal on a UNIX-flavored OS; why do no network interfaces
- show up in the list of interfaces in the "Interface:" field in the dialog
- box popped up by "Capture->Start"?
+ Gdk-ERROR **: Palettized display (256-colour) mode not supported on
+ Windows.
+ aborting....
- 5.9 Can Ethereal capture on (my T1/E1 line, SS7 links, etc.)?
+ when I try to run Ethereal on Windows?
- 5.10 How do I put an interface into promiscuous mode?
+ 5.7 I've installed Ethereal from Fink on Mac OS X; why is it very slow to
+ start up?
- 5.11 I can set a display filter just fine, but capture filters don't work.
+6. Crashes and other fatal errors:
- 5.12 I'm entering valid capture filters, but I still get "parse error"
- errors.
+ 6.1 When I run Ethereal, why do I get an error
- 5.13 I saved a filter and tried to use its name to filter the display, but I
- got an "Unexpected end of filter string" error.
+ Gtk-CRITICAL **: file gtkwindow.c: line 3107 (gtk_window_resize):
+ assertion `height > 0' failed.
- 5.14 Why am I seeing lots of packets with incorrect TCP checksums?
+ 6.2 I have an XXX network card on my machine; if I try to capture on it, why
+ does my machine crash or reset itself?
- 5.15 I've just installed Ethereal, and the traffic on my local LAN is
- boring.
+ 6.3 Why does my machine crash or reset itself when I select "Start" from the
+ "Capture" menu or select "Preferences" from the "Edit" menu?
- 5.16 When I run Ethereal on Solaris 8, it dies with a Bus Error when I start
- it.
+7. Capturing packets:
- 5.17 When I run Ethereal, I get an error
+ 7.1 When I use Ethereal to capture packets, why do I see only packets to and
+ from my machine, or not see all the traffic I'm expecting to see from or to
+ the machine I'm trying to monitor?
- Gtk-CRITICAL **: file gtkwindow.c: line 3107 (gtk_window_resize):
- assertion `height > 0' failed.
+ 7.2 When I capture with Ethereal, why can't I see any TCP packets other than
+ packets to and from my machine, even though another analyzer on the network
+ sees those packets?
- 5.18 When I run Tethereal with the "-x" option, it crashes with an error
+ 7.3 Why am I only seeing ARP packets when I try to capture traffic?
- "** ERROR **: file print.c: line 691 (print_line): should not be reached.
+ 7.4 Why am I not seeing any traffic when I try to capture traffic?
- 5.19 When I run Ethereal on Windows NT, it dies with a Dr. Watson error,
- reporting an "Integer division by zero" exception, when I start it.
+ 7.5 Can Ethereal capture on (my T1/E1 line, SS7 links, etc.)?
- 5.20 When I try to run Ethereal, it complains about sprint_realloc_objid
- being undefined.
+ 7.6 How do I put an interface into promiscuous mode?
- 5.21 I'm running Ethereal on Linux; why do my time stamps have only 100ms
- resolution, rather than 1us resolution?
+ 7.7 I can set a display filter just fine; why don't capture filters work?
- 5.22 I'm capturing packets on {Windows 95, Windows 98, Windows Me}; why are
- the time stamps on packets wrong?
+ 7.8 I'm entering valid capture filters; why do I still get "parse error"
+ errors?
+
+ 7.9 How can I capture packets with CRC errors?
+
+ 7.10 How can I capture entire frames, including the FCS?
+
+ 7.11 I'm capturing packets on a machine on a VLAN; why don't the packets I'm
+ capturing have VLAN tags?
+
+ 7.12 Why does Ethereal hang after I stop a capture?
+
+8. Capturing packets on Windows:
- 5.23 When I try to run Ethereal on Windows, it fails to run because it can't
- find packet.dll.
+ 8.1 I'm running Ethereal on Windows; why does some network interface on my
+ machine not show up in the list of interfaces in the "Interface:" field in
+ the dialog box popped up by "Capture->Start", and/or why does Ethereal give
+ me an error if I try to capture on that interface?
+
+ 8.2 I'm running Ethereal on Windows; why do no network interfaces show up in
+ the list of interfaces in the "Interface:" field in the dialog box popped up
+ by "Capture->Start"?
+
+ 8.3 I'm running Ethereal on Windows; why doesn't my serial port/ADSL
+ modem/ISDN modem show up in the list of interfaces in the "Interface:" field
+ in the dialog box popped up by "Capture->Start"?
- 5.24 I'm running Ethereal on Windows NT 4.0/Windows 2000/Windows XP/Windows
+ 8.4 I'm running Ethereal on Windows NT 4.0/Windows 2000/Windows XP/Windows
Server 2003; my machine has a PPP (dial-up POTS, ISDN, etc.) interface, and
it shows up in the "Interface" item in the "Capture Options" dialog box. Why
can no packets be sent on or received from that network while I'm trying to
capture traffic on that interface?
- 5.25 I'm running Ethereal on Windows 95/98/Me, on a machine with more than
- one network adapter of the same type; Ethereal shows all of those adapters
- with the same name, but I can't use any of those adapters other than the
- first one.
+ 8.5 I'm running Ethereal on Windows 95/98/Me, on a machine with more than
+ one network adapter of the same type; why does Ethereal show all of those
+ adapters with the same name, not letting me use any of those adapters other
+ than the first one?
- 5.26 I'm running Ethereal on Windows, and I'm not seeing any traffic being
- sent by the machine running Ethereal.
+ 8.6 I'm running Ethereal on Windows; why am I not seeing any traffic being
+ sent by the machine running Ethereal?
- 5.27 I'm trying to capture traffic but I'm not seeing any.
+ 8.7 When I capture on Windows in promiscuous mode, I can see packets other
+ than those sent to or from my machine; however, those packets show up with a
+ "Short Frame" indication, unlike packets to or from my machine. What should
+ I do to arrange that I see those packets in their entirety?
- 5.28 I have an XXX network card on my machine; if I try to capture on it, my
- machine crashes or resets itself.
+ 8.8 I'm capturing packets on {Windows 95, Windows 98, Windows Me}; why are
+ the time stamps on packets wrong?
- 5.29 My machine crashes or resets itself when I select "Start" from the
- "Capture" menu or select "Preferences" from the "Edit" menu.
+ 8.9 I'm trying to capture 802.11 traffic on Windows; why am I not seeing any
+ packets?
- 5.30 Does Ethereal work on Windows Me?
+ 8.10 I'm trying to capture 802.11 traffic on Windows; why am I seeing
+ packets received by the machine on which I'm capturing traffic, but not
+ packets sent by that machine?
- 5.31 Does Ethereal work on Windows XP?
+ 8.11 I'm trying to capture Ethernet VLAN traffic on Windows, and I'm
+ capturing on a "raw" Ethernet device rather than a "VLAN interface", so that
+ I can see the VLAN headers; why am I seeing packets received by the machine
+ on which I'm capturing traffic, but not packets sent by that machine?
- 5.32 Why doesn't Ethereal correctly identify RTP packets? It shows them only
- as UDP.
+9. Capturing packets on UN*Xes:
- 5.33 Why doesn't Ethereal show Yahoo Messenger packets in captures that
- contain Yahoo Messenger traffic?
+ 9.1 I'm running Ethereal on a UNIX-flavored OS; why does some network
+ interface on my machine not show up in the list of interfaces in the
+ "Interface:" field in the dialog box popped up by "Capture->Start", and/or
+ why does Ethereal give me an error if I try to capture on that interface?
- 5.34 Why do I get the error
+ 9.2 I'm running Ethereal on a UNIX-flavored OS; why do no network interfaces
+ show up in the list of interfaces in the "Interface:" field in the dialog
+ box popped up by "Capture->Start"?
- Gdk-ERROR **: Palettized display (256-colour) mode not supported on
- Windows.
- aborting....
+ 9.3 I'm capturing packets on Linux; why do the time stamps have only 100ms
+ resolution, rather than 1us resolution?
- when I try to run Ethereal on Windows?
+10. Capturing packets on wireless LANs:
- 5.35 When I capture on Windows in promiscuous mode, I can see packets other
- than those sent to or from my machine; however, those packets show up with a
- "Short Frame" indication, unlike packets to or from my machine. What should
- I do to arrange that I see those packets in their entirety?
+ 10.1 How can I capture raw 802.11 frames, including non-data (management,
+ beacon) frames?
- 5.36 I'm capturing packets on a machine on a VLAN; why don't the packets I'm
- capturing have VLAN tags?
+ 10.2 How do I capture on an 802.11 device in monitor mode?
- 5.37 How can I capture raw 802.11 frames, including non-data (management,
- beacon) frames?
+11. Viewing traffic:
- 5.38 How do I capture on an 802.11 device in monitor mode?
+ 11.1 Why am I seeing lots of packets with incorrect TCP checksums?
- 5.39 I'm trying to capture 802.11 traffic on Windows; why am I not seeing
- any packets?
+ 11.2 I've just installed Ethereal, and the traffic on my local LAN is
+ boring. Where can I find more interesting captures?
- 5.40 I'm trying to capture 802.11 traffic on Windows; why am I seeing
- packets received by the machine on which I'm capturing traffic, but not
- packets sent by that machine?
+ 11.3 Why doesn't Ethereal correctly identify RTP packets? It shows them only
+ as UDP.
- 5.41 How can I capture packets with CRC errors?
+ 11.4 Why doesn't Ethereal show Yahoo Messenger packets in captures that
+ contain Yahoo Messenger traffic?
- 5.42 How can I capture entire frames, including the FCS?
+12. Filtering traffic:
- 5.43 Why does Ethereal hang after I stop a capture?
+ 12.1 I saved a filter and tried to use its name to filter the display; why
+ do I get an "Unexpected end of filter string" error?
- 5.44 How can I search for, or filter, packets that have a particular string
+ 12.2 How can I search for, or filter, packets that have a particular string
anywhere in them?
- 5.45 How do I filter a capture to see traffic for virus XXX?
+ 12.3 How do I filter a capture to see traffic for virus XXX?
1. General Questions
Q 1.1: Where can I get help?
- A: Support is available on the ethereal-users mailing list. Subscription
- information and archives for all of Ethereal's mailing lists can be found at
- http://www.ethereal.com/lists
+ A: Community support is available on the ethereal-users mailing list.
+ Subscription information and archives for all of Ethereal's mailing lists
+ can be found at http://www.ethereal.com/lists. An IRC channel dedicated to
+ Ethereal can be found at irc://irc.freenode.net/ethereal.
+
+ Commercial support, training, and development services are available from
+ Ethereal Software.
Q 1.2: How much does Ethereal cost?
Q 1.5: What protocols are currently supported?
- A: There are currently 683 supported protocols and media, listed below.
+ A: There are currently 750 supported protocols and media, listed below.
Descriptions can be found in the ethereal(1) man page.
3Com XNS Encapsulation
3GPP2 A11
- 802.1q Virtual LAN
- 802.1x Authentication
- AAL type 2 signalling protocol - Capability set 1 (Q.2630.1)
+ 3com Network Jack
+ 802.1Q Virtual LAN
+ 802.1X Authentication
+ AAL type 2 signalling protocol (Q.2630)
ACN
AFS (4.0) Replication Server call declarations
AIM Administrative
Alteon - Transparent Proxy Cache Protocol
Andrew File System (AFS)
Apache JServ Protocol v1.3
+ Apple Filing Protocol
Apple IP-over-IEEE 1394
- AppleTalk Filing Protocol
AppleTalk Session Protocol
AppleTalk Transaction Protocol packet
Appletalk Address Resolution Protocol
Aruba - Aruba Discovery Protocol
Async data over ISDN (V.120)
Asynchronous Layered Coding
+ AudioCodes Trunk Trace
Authentication Header
BACnet Virtual Link Control
BEA Tuxedo
CBAPhysicalDevice
CCSDS
CDS Clerk Server Calls
+ CSM_ENCAPS
Camel
Cast Client Control Protocol
Certificate Management Protocol
Cisco NetFlow
Cisco SLARP
Cisco Session Management
+ Cisco Wireless Layer 2
Clearcase NFS
CoSine IPNOS L2 debug output
+ Common Image Generator Interface
Common Industrial Protocol
Common Open Policy Service
Common Unix Printing System (CUPS) Browsing Protocol
+ Compressed Data Type
Compuserve GIF
+ Computer Interface to Message Distribution
Configuration Test Protocol (loopback)
Connectionless Lightweight Directory Access Protocol
Coseventcomm Dissector Using GIOP API
DCOM IDispatch
DCOM IRemoteActivation
DCOM OXID Resolver
+ DEC DNA Routing Protocol
DEC Spanning Tree Protocol
DFS Calls
DG Gryphon Protocol
DHCP Failover
DHCPv6
DICOM
+ DLT_USER_A
+ DLT_USER_B
+ DLT_USER_C
+ DLT_USER_D
DNS Control Program Server
DOCSIS 1.1
DOCSIS Appendix C TLV's
Data
Data Link SWitching
Data Stream Interface
+ Datagram Congestion Control Protocol
Datagram Delivery Protocol
Decompressed SigComp message as raw text
Diameter Protocol
Distance Vector Multicast Routing Protocol
Distcc Distributed Compiler
Distributed Checksum Clearinghouse Protocol
+ Distributed Interactive Simulation
Distributed Network Protocol 3.0
Domain Name Service
+ Dublin Core Metadata (DC)
Dynamic DNS Tools Protocol
Dynamic Trunking Protocol
ENTTEC
Ethernet over IP
Extended Security Services
Extensible Authentication Protocol
+ Extreme Discovery Protocol
FC Extended Link Svc
FC Fabric Configuration Server
FCIP
GSM A-I/F BSSMAP
GSM A-I/F DTAP
GSM A-I/F RP
+ GSM Mobile Application
GSM SMS TPDU (GSM 03.40)
GSM Short Message Service User Data
- GSM_MobileAPplication
+ GSM_SS
+ GSS-API Generic Security Service Application Program Interface
General Inter-ORB Protocol
Generic Routing Encapsulation
- Generic Security Service Application Program Interface
Gnutella Protocol
H.248 MEGACO
+ H.324/CCSRL
+ H.324/SRP
+ H221NonStandard
H235-SECURITY-MESSAGES
+ H323-MESSAGES
HP Extended Local-Link Control
HP Remote Maintenance Protocol
HP Switch Protocol
IEEE 802.11 wireless LAN management frame
IEEE802a OUI Extended Ethertype
ILMI
- INAP
IP Device Control (SS7 over IP)
IP Over FC
IP Payload Compression
ISO 8073 COTP Connection-Oriented Transport Protocol
ISO 8327-1 OSI Session Protocol
ISO 8473 CLNP ConnectionLess Network Protocol
+ ISO 8571 FTAM
ISO 8602 CLTP ConnectionLess Transport Protocol
+ ISO 8650-1 OSI Association Control Service
ISO 8823 OSI Presentation Protocol
ISO 9542 ESIS Routeing Information Exchange Protocol
+ ISUP Thin Protocol
ISystemActivator ISystemActivator Resolver
+ ITU M.3100 Generic Network Information Model
ITU-T E.164 number
+ ITU-T Recommendation H.223
ITU-T Recommendation H.261
+ ITU-T Recommendation H.263
ITU-T Recommendation H.263 RTP Payload header (RFC2190)
InMon sFlow
Information Access Protocol
+ Init shutdown service
Intel ANS probe
+ Intelligent Network Application Protocol
Intelligent Platform Management Interface
Inter-Access-Point Protocol
Inter-Asterisk eXchange v2
IrCOMM Protocol
IrDA Link Access Protocol
IrDA Link Management Protocol
+ IuUP
JPEG File Interchange Format
+ JXTA Connection Welcome Message
+ JXTA Message
+ JXTA Message Framing
JXTA P2P
+ JXTA UDP
Jabber XML Messaging
Java RMI
Java Serialization
Juniper
+ K12xx
Kerberized Internet Negotiation of Key
Kerberos
Kerberos Administration
Layer 2 Tunneling Protocol
Light Weight DNS RESolver (BIND9)
Lightweight Directory Access Protocol
+ Lightweight User Datagram Protocol
Line Printer Daemon Protocol
Line-based text data
Link Access Procedure Balanced (LAPB)
Link Access Procedure Balanced Ethernet (LAPBETHER)
Link Access Procedure, Channel D (LAPD)
+ Link Layer Discovery Protocol
Link Management Protocol (LMP)
Linux cooked-mode capture
Local Management Interface
Log Message
Logical Link Control GPRS
Logical-Link Control
+ Logical-Link Control Basic Format XID
Logotype Certificate Extensions
Lucent/Ascend debug output
MAC Control
MDS Header
MEGACO
MIME Multipart Media Encapsulation
+ MMS
MMS Message Encapsulation
MS Kpasswd
+ MS Network Load Balancing
MS Proxy Protocol
MSN Messenger Service
MSNIP: Multicast Source Notification of Interest Protocol
MTP 2 User Adaptation Layer
MTP 3 User Adaptation Layer
MTP2 Peer Adaptation Layer
+ MULTIMEDIA-SYSTEM-CONTROL
Media Gateway Control Protocol
Media Type
- Media Type: application/x-jxta-msg
Media Type: message/http
+ Message Session Relay Protocol
Message Transfer Part Level 2
Message Transfer Part Level 3
Message Transfer Part Level 3 Management
Meta Analysis Tracing Engine
+ Microsoft AT-Scheduler Service
Microsoft Distributed File System
Microsoft Distributed Link Tracking Server Service
Microsoft Encrypted File System Service
Microsoft File Replication Service
Microsoft File Replication Service API
Microsoft Local Security Architecture
+ Microsoft Media Server
Microsoft Messenger Service
Microsoft Network Logon
Microsoft Plug and Play service
- Microsoft Registry
Microsoft Routing and Remote Access Service
Microsoft Security Account Manager
Microsoft Server Service
Microsoft Service Control
Microsoft Spool Subsystem
- Microsoft Task Scheduler Service
Microsoft Telephony API Service
Microsoft Windows Browser Protocol
Microsoft Windows Lanman Remote API Protocol
Microsoft Windows Logon Protocol (Old)
Microsoft Workstation Service
Mobile IP
- Mobile IPv6
+ Mobile IPv6 / Network Mobility
Modbus/TCP
Monotone Netsync
Mount Service
Multicast Source Discovery Protocol
Multiprotocol Label Switching Echo
MySQL Protocol
+ NBMA Next Hop Resolution Protocol
NFSACL
NFSAUTH
NIS+
Network Status Monitor Protocol
Network Time Protocol
Nortel SONMP
+ Novell Cluster Services
Novell Distributed Print System
Novell Modular Authentication Service
+ Novell SecretStore Services
Null/Loopback
- OSI ISO 8571 FTAM Protocol
- OSI ISO/IEC 10035-1 ACSE Protocol
Online Certificate Status Protocol
Open Policy Service Interface
Open Shortest Path First
PROFINET DCP
PROFINET IO
PROFINET Real-Time Protocol
+ P_Mul (ACP142)
Packed Encoding Rules (ASN.1 X.691)
Packet Cable Lawful Intercept
PacketCable
+ Parallel Virtual File System
+ Parlay Dissector Using GIOP API
Plan 9 9P
Point-to-Point Protocol
Point-to-Point Tunnelling Protocol
PostgreSQL
Pragmatic General Multicast
Precision Time Protocol (IEEE1588)
+ Printer Access Protocol
Prism
Privilege Server operations
Protocol Independent Multicast
Remote Procedure Call
Remote Program Load
Remote Quota
+ Remote Registry Service
Remote Shell
- Remote Shutdown
Remote Wall protocol
Remote sec_login preauth interface.
Resource ReserVation Protocol (RSVP)
SMB (Server Message Block Protocol)
SMB MailSlot Protocol
SMB Pipe Protocol
+ SMB2 (Server Message Block Protocol version 2)
SNA-over-Ethernet
SNMP Multiplex Protocol
SPNEGO-KRB5
SSCF-NNI
SSCOP
SSH Protocol
+ STANAG 4406 Military Message
+ STANAG 5066 (SIS layer)
Secure Socket Layer
Sequenced Packet Protocol
Sequenced Packet eXchange
Signalling Connection Control Part Management
Simple Mail Transfer Protocol
Simple Network Management Protocol
+ Simple Protected Negotiation
Simple Traversal of UDP Through NAT
Sinec H1 Protocol
Sipfrag
Socks Protocol
SoulSeek Protocol
Spanning Tree Protocol
- Spnego
Stream Control Transmission Protocol
Subnetwork Dependent Convergence Protocol
Symantec Enterprise Firewall
+ Synchronized Multimedia Integration Language
Synchronous Data Link Control (SDLC)
+ Synergy
Syslog message
Systems Network Architecture
Systems Network Architecture XID
TACACS+
TDMA RTmac Discipline
TEI Management Procedure, Channel D (LAPD)
- TPKT
+ TPKT - ISO on TCP - RFC1006
Tabular Data Stream
+ Tango Dissector Using GIOP API
Tazmen Sniffer Protocol
Telnet
Teredo IPv6 over UDP tunneling
+ The Armagetron Advanced OpenGL Tron clone
Time Protocol
Time Synchronization Protocol
Tiny Transport Protocol
Token-Ring Media Access Control
Transaction Capabilities Application Part
Transmission Control Protocol
+ Transparent Inter Process Communication(TIPC)
Transparent Network Substrate Protocol
Transport Adapter Layer Interface v1.0, RFC 3094
Trivial File Transfer Protocol
UDP Encapsulation of IPsec Packets
+ UTRAN Iub interface NBAP signalling
+ UTRAN Iur interface Radio Network Subsystem Application Part
Universal Computer Protocol
Unlicensed Mobile Access
User Datagram Protocol
Virtual Trunking Protocol
WAP Binary XML
WAP Session Initiation Request
+ WINS (Windows Internet Name Service) Replication
Web Cache Coordination Protocol
WebSphere MQ
WebSphere MQ Programmable Command Formats
Wireless Session Protocol
Wireless Transaction Protocol
Wireless Transport Layer Security
+ Wlan Certificate Extension
X Display Manager Control Protocol
+ X.228 OSI Reliable Transfer Service
X.25
X.25 over TCP
X.29
+ X.411 Message Transfer Service
+ X.420 File Transfer Body Part
+ X.420 Information Object
+ X.501 Directory Operational Binding Management Protocol
X.509 Authentication Framework
X.509 Certificate Extensions
X.509 Information Framework
X.509 Selected Attribute Types
+ X.519 Directory Access Protocol
+ X.519 Directory Information Shadowing Protocol
+ X.519 Directory System Protocol
+ X.880 OSI Remote Operations Service
X11
X711 CMIP
Xyplex
eDonkey Protocol
eXtensible Markup Language
giFT Internet File Transfer
- h225
- h245
h450
+ iFCP
iSCSI
iSNS
+ iTunes podCast rss elements
+ rss
Q 1.6: Are there any plans to support {your favorite protocol}?
it means "we don't know whether it can capture on them"; we expect that it
will be able to capture on many of them, but we haven't tried it ourselves -
if you try one of those types and it works, please send an update to
- ethereal-web[AT]ethereal.com ).
+ ethereal-web[AT]ethereal.com).
It can also read a variety of capture file formats, including:
* AG Group/WildPackets EtherPeek/TokenPeek/AiroPeek/EtherHelp/Packet
like an appropriate name for something that started out as an Ethernet
analyzer.
+ Q 1.10: Does Ethereal work on Windows Me?
+
+ A: Yes, but if you want to capture packets, you will need to install the
+ latest version of WinPcap, as 2.02 and earlier versions of WinPcap didn't
+ support Windows Me. You should also install the latest version of Ethereal
+ as well.
+
+ Q 1.11: Does Ethereal work on Windows XP?
+
+ A: Yes, but if you want to capture packets, you will need to install the
+ latest version of WinPcap, as 2.2 and earlier versions of WinPcap didn't
+ support Windows XP.
+
2. Downloading Ethereal
- Q 2.1: I downloaded the Win32 installer, but when I try to run it, I get an
- error.
+ Q 2.1: Why do I get an error when I try to run the Win32 installer?
A: The program you used to download it may have downloaded it incorrectly.
Web browsers sometimes may do this.
rather than ASCII mode, by using the binary command before transferring the
file.
- Q 2.2: When I try to download the WinPcap driver and library, I can't get to
- the WinPcap Web site.
+ Q 2.2: Why can't I get to the WinPcap Web site in order to download WinPcap?
A: As is the case with all Web sites, that site won't necessarily always be
accessible; the server may be down due to a problem or down for maintenance,
or there may be a networking problem between you and the server. You should
try again later, or try the local mirror or the Wiretapped.net mirror.
+ Note that current Ethereal releases include an installer for WinPcap.
+
3. Installing Ethereal
- Q 3.1: I installed an Ethereal RPM, but Ethereal doesn't seem to be
- installed; only Tethereal is installed.
+ Q 3.1: I installed an Ethereal RPM; why did it install Tethereal but not
+ Ethereal?
A: Older versions of the Red Hat RPMs for Ethereal put only the non-GUI
components into the ethereal RPM, the fact that Ethereal is a GUI program
4. Building Ethereal
- Q 4.1: The configure script can't find pcap.h or bpf.h, but I have libpcap
- installed.
+ Q 4.1: I have libpcap installed; why did the configure script not find
+ pcap.h or bpf.h?
A: Are you sure pcap.h and bpf.h are installed? The official distribution of
libpcap only installs the libpcap.a library file when "make install" is run.
There is a bug in that version of automake that causes this problem; upgrade
to a later version of automake (1.6 or later).
- Q 4.3: The link fails with a number of "Output line too long." messages
- followed by linker errors.
+ Q 4.3: Why does the linker fail with a number of "Output line too long."
+ messages followed by linker errors when I try to buil Ethereal?
A: The version of the sed command on your system is incapable of handling
very long lines. On Solaris, for example, /usr/bin/sed has a line length
the directory in which it is installed before searching the directory with
the version of sed that came with the OS should make the problem go away.
- Q 4.4: The link fails on Solaris because plugin_list is undefined.
+ Q 4.4: When I try to build Ethereal on Solaris, why does the link fail
+ complaining that plugin_list is undefined?
A: This appears to be due to a problem with some versions of the GTK+ and
GLib packages from www.sunfreeware.org; un-install those packages, and try
www.sunfreeware.org, and the problem persists, un-install them and try
installing one of the other versions mentioned.)
- Q 4.5: The build fails on Windows because of conflicts between winsock.h and
- winsock2.h.
+ Q 4.5: When I try to build Ethereal on Windows, why does the build fail
+ because of conflicts between winsock.h and winsock2.h?
A: As of Ethereal 0.9.5, you must install WinPcap 2.3 or later, and the
corresponding version of the developer's pack, in order to be able to
Note that the installed version of the developer's pack should be the same
version as the version of WinPcap you have installed.
-5. Using Ethereal
+5. Starting Ethereal
+
+ Q 5.1: Why does Ethereal crash with a Bus Error when I try to run it on
+ Solaris 8?
+
+ A: Some versions of the GTK+ library from www.sunfreeware.org appear to be
+ buggy, causing Ethereal to drop core with a Bus Error. Un-install those
+ packages, and try getting the 1.2.10 version from that site, or the version
+ from The Written Word, or the version from Sun's GNOME distribution, or the
+ version from the supplemental software CD that comes with the Solaris media
+ kit, or build it from source from the GTK Web site. Update the GLib library
+ to the 1.2.10 version, from the same source, as well. (If you get the 1.2.10
+ versions from www.sunfreeware.org, and the problem persists, un-install them
+ and try installing one of the other versions mentioned.)
+
+ Similar problems may exist with older versions of GTK+ for earlier versions
+ of Solaris.
+
+ Q 5.2: When I run Tethereal with the "-x" option, why does it crash with an
+ error
+
+ "** ERROR **: file print.c: line 691 (print_line): should not be reached.
+
+ A: This is a bug in Ethereal 0.10.0a, which is fixed in 0.10.1 and later
+ releases. To work around the bug, don't use "-x" unless you're also using
+ "-V"; note that "-V" produces a full dissection of each packet, so you might
+ not want to use it.
+
+ Q 5.3: When I run Ethereal on Windows NT, why does it die with a Dr. Watson
+ error, reporting an "Integer division by zero" exception, when I start it?
+
+ A: In at least some case, this appears to be due to using the default VGA
+ driver; if that's not the correct driver for your video card, try running
+ the correct driver for your video card.
+
+ Q 5.4: When I try to run Ethereal, why does it complain about
+ sprint_realloc_objid being undefined?
+
+ A: Ethereal can only be linked with version 4.2.2 or later of UCD SNMP. Your
+ version of Ethereal was dynamically linked with such a version of UCD SNMP;
+ however, you have an older version of UCD SNMP installed, which means that
+ when Ethereal is run, it tries to link to the older version, and fails. You
+ will have to replace that version of UCD SNMP with version 4.2.2 or a later
+ version.
+
+ Q 5.5: When I try to run Ethereal on Windows, why does it fail to run with a
+ complaint that it can't find packet.dll?
+
+ A: In older versions of Ethereal, there were two binary distributions
+ available for Windows, one that supported capturing packets, and one that
+ didn't. The version that supported capturing packets required that you
+ install the WinPcap driver; if you didn't install it, it would fail to run
+ because it couldn't find packet.dll.
+
+ The current version of Ethereal has only one binary distribution for
+ Windows; that version will check whether WinPcap is installed and, if it's
+ not, will disable support for packet capture.
+
+ The WinPcap driver and libraries can be downloaded from the WinPcap Web
+ site, the local mirror of the WinPcap Web site, or the Wiretapped.net mirror
+ of the WinPcap site.
+
+ Q 5.6: Why do I get the error
+
+ Gdk-ERROR **: Palettized display (256-colour) mode not supported on
+ Windows.
+ aborting....
+
+ when I try to run Ethereal on Windows?
+
+ A: Ethereal is built using the GTK+ toolkit, which supports most
+ UNIX-flavored OSes, and also supports Windows.
+
+ Windows versions of Ethereal before 0.9.14 were built with an older version
+ of that toolkit, which didn't support 256-color mode on Windows - it
+ required HiColor (16-bit colors) or more.
+
+ Windows versions of Ethereal 0.9.14 and later are built with a version of
+ that toolkit that supports 256-color mode; upgrade to the current version of
+ Ethereal if you want to run on a display in 256-color mode.
+
+ Q 5.7: I've installed Ethereal from Fink on Mac OS X; why is it very slow to
+ start up?
+
+ A: When an application is installed on OS X, prior to 10.4, it is usually
+ "prebound" to speed up launching the application. (That's what the
+ "Optimizing" phase of installation is.) Fink normally performs prebinding
+ automatically when you install a package. However, in some rare cases, for
+ whatever reason the prebinding caches get corrupt, and then not only does
+ prebinding fail, but startup actually becomes much slower, because the
+ system tries in vain to perform prebinding "on the fly" as you launch the
+ application. This fails, causing sometimes huge delays. To fix the
+ prebinding caches, run the command
+ sudo /sw/var/lib/fink/prebound/update-package-prebinding.pl -f
+
+6. Crashes and other fatal errors
+
+ Q 6.1: When I run Ethereal, why do I get an error
+
+ Gtk-CRITICAL **: file gtkwindow.c: line 3107 (gtk_window_resize):
+ assertion `height > 0' failed.
+
+ A: This is a bug in Ethereal 0.10.5 and 0.10.5a, which is fixed in Ethereal
+ 0.10.6 and later releases.
+
+ Q 6.2: I have an XXX network card on my machine; if I try to capture on it,
+ why does my machine crash or reset itself?
+
+ A: This is almost certainly a problem with one or more of:
+ * the operating system you're using;
+ * the device driver for the interface you're using;
+ * the libpcap/WinPcap library and, if this is Windows, the WinPcap device
+ driver;
+
+ so:
+ * if you are using Windows, see the WinPcap support page (or the local
+ mirror of that page) - check the "Submitting bugs" section;
+ * if you are using some Linux distribution, some version of BSD, or some
+ other UNIX-flavored OS, you should report the problem to the company or
+ organization that produces the OS (in the case of a Linux distribution,
+ report the problem to whoever produces the distribution).
+
+ Q 6.3: Why does my machine crash or reset itself when I select "Start" from
+ the "Capture" menu or select "Preferences" from the "Edit" menu?
- Q 5.1: When I use Ethereal to capture packets, I see only packets to and
- from my machine, or I'm not seeing all the traffic I'm expecting to see from
- or to the machine I'm trying to monitor.
+ A: Both of those operations cause Ethereal to try to build a list of the
+ interfaces that it can open; it does so by getting a list of interfaces and
+ trying to open them. There is probably an OS, driver, or, for Windows,
+ WinPcap bug that causes the system to crash when this happens; see the
+ previous question.
+
+7. Capturing packets
+
+ Q 7.1: When I use Ethereal to capture packets, why do I see only packets to
+ and from my machine, or not see all the traffic I'm expecting to see from or
+ to the machine I'm trying to monitor?
A: This might be because the interface on which you're capturing is plugged
into an Ethernet or Token Ring switch; on a switched network, unicast
network interfaces at the same time), so it may be that Windows drivers for
those interfaces don't support promiscuous mode.
- Q 5.2: I can't see any TCP packets other than packets to and from my
- machine, even though another analyzer on the network sees those packets.
+ Q 7.2: When I capture with Ethereal, why can't I see any TCP packets other
+ than packets to and from my machine, even though another analyzer on the
+ network sees those packets?
A: You're probably not seeing any packets other than unicast packets to or
from your machine, and broadcast and multicast packets; a switch will
I.e., this is probably the same question as this earlier one; see the
response to that question.
- Q 5.3: I'm only seeing ARP packets when I try to capture traffic.
+ Q 7.3: Why am I only seeing ARP packets when I try to capture traffic?
A: You're probably on a switched network, and running Ethereal on a machine
that's not sending traffic to the switch and not being sent any traffic from
I.e., this is probably the same question as this earlier one; see the
response to that question.
- Q 5.4: I'm running Ethereal on Windows; why does some network interface on
- my machine not show up in the list of interfaces in the "Interface:" field
- in the dialog box popped up by "Capture->Start", and/or why does Ethereal
- give me an error if I try to capture on that interface?
+ Q 7.4: Why am I not seeing any traffic when I try to capture traffic?
- A: If you are running Ethereal on Windows NT 4.0, Windows 2000, Windows XP,
- or Windows Server 2003, and this is the first time you have run a
- WinPcap-based program (such as Ethereal, or Tethereal, or WinDump, or
- Analyzer, or...) since the machine was rebooted, you need to run that
- program from an account with administrator privileges; once you have run
- such a program, you will not need administrator privileges to run any such
- programs until you reboot.
+ A: Is the machine running Ethereal sending out any traffic on the network
+ interface on which you're capturing, or receiving any traffic on that
+ network, or is there any broadcast traffic on the network or multicast
+ traffic to a multicast group to which the machine running Ethereal belongs?
- If you are running on Windows 95/98/Me, or if you are running on Windows NT
- 4.0/Windows 2000/Windows XP/Windows Server 2003 and have administrator
- privileges or a WinPcap-based program has been run with those privileges
- since the machine rebooted, this problem might clear up if you completely
- un-install WinPcap and then re-install it.
+ If not, this may just be a problem with promiscuous sniffing, either due to
+ running on a switched network or a dual-speed hub, or due to problems with
+ the interface not supporting promiscuous mode; see the response to this
+ earlier question.
- If that doesn't work, then note that Ethereal relies on the WinPcap library,
- on the WinPcap device driver, and on the facilities that come with the OS on
- which it's running in order to do captures.
+ Otherwise, on Windows, see the response to this question and, on a
+ UNIX-flavored OS, see the response to this question.
- Therefore, if the OS, the WinPcap library, or the WinPcap driver don't
- support capturing on a particular network interface device, Ethereal won't
- be able to capture on that device.
+ Q 7.5: Can Ethereal capture on (my T1/E1 line, SS7 links, etc.)?
- Note that:
- 1. 2.02 and earlier versions of the WinPcap driver and library that
- Ethereal uses for packet capture didn't support Token Ring interfaces;
- versions 2.1 and later support Token Ring, and the current version of
- Ethereal works with (and, in fact, requires) WinPcap 2.1 or later.
- If you are having problems capturing on Token Ring interfaces, and you
- have WinPcap 2.02 or an earlier version of WinPcap installed, you should
- uninstall WinPcap, download and install the current version of WinPcap,
- and then install the latest version of Ethereal.
- 2. On Windows 95, 98, or Me, sometimes more than one interface will be
- given the same name; if that is the case, you will only be able to
- capture on one of those interfaces - it's not clear to which one the
- name, when used in a WinPcap-based application, will refer. For example,
- if you have a PPP serial interface and a VPN interface, they might show
- up with the same name, for example "ppp-mac", and if you try to capture
- on "ppp-mac", it might not capture on the interface you're currently
- using. In that case, you might, for example, have to remove the VPN
- interface from the system in order to capture on the PPP serial
- interface.
- 3. WinPcap 2.3 has problems supporting PPP WAN interfaces on Windows NT
- 4.0, Windows 2000, Windows XP, and Windows Server 2003, and, to avoid
- those problems, support for PPP WAN interfaces on those versions of
- Windows has been disabled in WinPcap 3.0. Regular dial-up lines, ISDN
- lines, ADSL connections using PPPoE or PPPoA, and various other lines
- such as T1/E1 lines are all PPP interfaces, so those interfaces might
- not show up on the list of interfaces in the "Capture Options" dialog on
- those OSes.
- On Windows 2000 and later, installing the beta version of WinPcap 3.1
- might help, although, as it's a beta version, that might cause some
- other problems that don't occur with older versions of WinPcap; you
- should report those problems to the WinPcap developers, so that they can
- try to fix those problems before the final version of WinPcap 3.1 is
- released. WinPcap 3.1 will not support PPP captures on Windows NT 4.0.
- See the Ethereal Wiki item on PPP capturing for details.
- 4. WinPcap prior to 3.0 does not support multiprocessor machines (note that
- machines with a single multi-threaded processor, such as Intel's new
- multi-threaded x86 processors, are multiprocessor machines as far as the
- OS and WinPcap are concerned), and recent 2.x versions of WinPcap refuse
- to operate if they detect that they're running on a multiprocessor
- machine, which means that they may not show any network interfaces. You
- will need to use WinPcap 3.0 to capture on a multiprocessor machine.
-
- If an interface doesn't show up in the list of interfaces in the
- "Interface:" field, and you know the name of the interface, try entering
- that name in the "Interface:" field and capturing on that device.
-
- If the attempt to capture on it succeeds, the interface is somehow not being
- reported by the mechanism Ethereal uses to get a list of interfaces. Try
- listing the interfaces with WinDump; see the WinDump Web site or the local
- mirror of the WinDump Web site for information on using WinDump.
-
- You would run WinDump with the -D flag; if it lists the interface, please
- report this to ethereal-dev@ethereal.com giving full details of the problem,
- including
- * the operating system you're using, and the version of that operating
- system;
- * the type of network device you're using;
- * the output of WinDump.
-
- If WinDump does not list the interface, this is almost certainly a problem
- with one or more of:
- * the operating system you're using;
- * the device driver for the interface you're using;
- * the WinPcap library and/or the WinPcap device driver;
-
- so first check the WinPcap FAQ, the local mirror of that FAQ, or the
- Wiretapped.net mirror of that FAQ, to see if your problem is mentioned
- there. If not, then see the WinPcap support page (or the local mirror of
- that page) - check the "Submitting bugs" section.
-
- If you are having trouble capturing on a particular network interface, first
- try capturing on that device with WinDump; see the WinDump Web site or the
- local mirror of the WinDump Web site for information on using WinDump.
-
- If you can capture on the interface with WinDump, send mail to
- ethereal-users@ethereal.com giving full details of the problem, including
- * the operating system you're using, and the version of that operating
- system;
- * the type of network device you're using;
- * the error message you get from Ethereal.
-
- If you cannot capture on the interface with WinDump, this is almost
- certainly a problem with one or more of:
- * the operating system you're using;
- * the device driver for the interface you're using;
- * the WinPcap library and/or the WinPcap device driver;
-
- so first check the WinPcap FAQ, the local mirror of that FAQ, or the
- Wiretapped.net mirror of that FAQ, to see if your problem is mentioned
- there. If not, then see the WinPcap support page (or the local mirror of
- that page) - check the "Submitting bugs" section.
-
- You may also want to ask the ethereal-users@ethereal.com and the
- winpcap-users@winpcap.org mailing lists to see if anybody happens to know
- about the problem and know a workaround or fix for the problem. (Note that
- you will have to subscribe to that list in order to be allowed to mail to
- it; see the WinPcap support page, or the local mirror of that page, for
- information on the mailing list.) In your mail, please give full details of
- the problem, as described above, and also indicate that the problem occurs
- with WinDump, not just with Ethereal.
-
- Q 5.5: I'm running Ethereal on Windows; why do no network interfaces show up
- in the list of interfaces in the "Interface:" field in the dialog box popped
- up by "Capture->Start"?
-
- A: This is really the same question as the previous one; see the response to
- that question.
-
- Q 5.6: I'm running Ethereal on Windows; why doesn't my serial port/ADSL
- modem/ISDN modem show up in the list of interfaces in the "Interface:" field
- in the dialog box popped up by "Capture->Start"?
-
- A: Internet access on those devices is often done with the Point-to-Point
- (PPP) protocol; WinPcap 2.3 has problems supporting PPP WAN interfaces on
- Windows NT 4.0, Windows 2000, Windows XP, and Windows Server 2003, and, to
- avoid those problems, support for PPP WAN interfaces on those versions of
- Windows has been disabled in WinPcap 3.0.
-
- On Windows 2000 and later, installing the beta version of WinPcap 3.1 might
- help, although, as it's a beta version, that might cause some other problems
- that don't occur with older versions of WinPcap; you should report those
- problems to the WinPcap developers, so that they can try to fix those
- problems before the final version of WinPcap 3.1 is released. WinPcap 3.1
- will not support PPP captures on Windows NT 4.0. See the Ethereal Wiki item
- on PPP capturing for details.
-
- Q 5.7: I'm running Ethereal on a UNIX-flavored OS; why does some network
- interface on my machine not show up in the list of interfaces in the
- "Interface:" field in the dialog box popped up by "Capture->Start", and/or
- why does Ethereal give me an error if I try to capture on that interface?
-
- A: You may need to run Ethereal from an account with sufficient privileges
- to capture packets, such as the super-user account, or may need to give your
- account sufficient privileges to capture packets. Only those interfaces that
- Ethereal can open for capturing show up in that list; if you don't have
- sufficient privileges to capture on any interfaces, no interfaces will show
- up in the list. See the Ethereal Wiki item on capture privileges for details
- on how to give a particular account or account group capture privileges on
- platforms where that can be done.
-
- If you are running Ethereal from an account with sufficient privileges, then
- note that Ethereal relies on the libpcap library, and on the facilities that
- come with the OS on which it's running in order to do captures. On some
- OSes, those facilities aren't present by default; see the Ethereal Wiki item
- on adding capture support for details.
-
- And, even if you're running with an account that has sufficient privileges
- to capture, and capture support is present in your OS, if the OS or the
- libpcap library don't support capturing on a particular network interface
- device or particular types of devices, Ethereal won't be able to capture on
- that device.
-
- On Solaris, note that libpcap 0.6.2 and earlier didn't support Token Ring
- interfaces; the current version, 0.7.2, does support Token Ring, and the
- current version of Ethereal works with libcap 0.7.2 and later.
-
- If an interface doesn't show up in the list of interfaces in the
- "Interface:" field, and you know the name of the interface, try entering
- that name in the "Interface:" field and capturing on that device.
-
- If the attempt to capture on it succeeds, the interface is somehow not being
- reported by the mechanism Ethereal uses to get a list of interfaces; please
- report this to ethereal-dev@ethereal.com giving full details of the problem,
- including
- * the operating system you're using, and the version of that operating
- system (for Linux, give both the version number of the kernel and the
- name and version number of the distribution you're using);
- * the type of network device you're using.
-
- If you are having trouble capturing on a particular network interface, and
- you've made sure that (on platforms that require it) you've arranged that
- packet capture support is present, as per the above, first try capturing on
- that device with tcpdump.
-
- If you can capture on the interface with tcpdump, send mail to
- ethereal-users@ethereal.com giving full details of the problem, including
- * the operating system you're using, and the version of that operating
- system (for Linux, give both the version number of the kernel and the
- name and version number of the distribution you're using);
- * the type of network device you're using;
- * the error message you get from Ethereal.
-
- If you cannot capture on the interface with tcpdump, this is almost
- certainly a problem with one or more of:
- * the operating system you're using;
- * the device driver for the interface you're using;
- * the libpcap library;
-
- so you should report the problem to the company or organization that
- produces the OS (in the case of a Linux distribution, report the problem to
- whoever produces the distribution).
-
- You may also want to ask the ethereal-users@ethereal.com and the
- tcpdump-workers@tcpdump.org mailing lists to see if anybody happens to know
- about the problem and know a workaround or fix for the problem. In your
- mail, please give full details of the problem, as described above, and also
- indicate that the problem occurs with tcpdump not just with Ethereal.
-
- Q 5.8: I'm running Ethereal on a UNIX-flavored OS; why do no network
- interfaces show up in the list of interfaces in the "Interface:" field in
- the dialog box popped up by "Capture->Start"?
-
- A: This is really the same question as the previous one; see the response to
- that question.
-
- Q 5.9: Can Ethereal capture on (my T1/E1 line, SS7 links, etc.)?
-
- A: Ethereal can only capture on devices supported by libpcap/WinPcap. On
- most OSes, only devices that can act as network interfaces of the type that
- support IP are supported as capture devices for libpcap/WinPcap, although
- the device doesn't necessarily have to be running as an IP interface in
- order to support traffic capture.
+ A: Ethereal can only capture on devices supported by libpcap/WinPcap. On
+ most OSes, only devices that can act as network interfaces of the type that
+ support IP are supported as capture devices for libpcap/WinPcap, although
+ the device doesn't necessarily have to be running as an IP interface in
+ order to support traffic capture.
On Linux and FreeBSD, libpcap 0.8 and later support the API for Endace
Measurement Systems' DAG cards, so that a system with one of those cards,
of Ethereal and a shared libpcap library with DAG support, in order to do so
with Ethereal. You should ask Endace whether that could be used to capture
traffic on, for example, your T1/E1 link.
- There is currently no hardware to support capturing on SS7 links with
- libpcap. (Note that the fact that Ethereal includes dissectors for many SS7
- protocols doesn't imply that it can capture traffic from SS7 links; those
- protocols can be run over Internet protocols.)
+ See the SS7 capture setup page on the Ethereal Wiki for current information
+ on capturing SS7 traffic on TDM links.
- Q 5.10: How do I put an interface into promiscuous mode?
+ Q 7.6: How do I put an interface into promiscuous mode?
A: By not disabling promiscuous mode when running Ethereal or Tethereal.
I.e., this is probably the same question as this earlier one; see the
response to that question.
- Q 5.11: I can set a display filter just fine, but capture filters don't
- work.
+ Q 7.7: I can set a display filter just fine; why don't capture filters work?
A: Capture filters currently use a different syntax than display filters.
Here's the corresponding section from the ethereal(1) man page:
The capture filter syntax used by libpcap can be found in the tcpdump(8) man
page.
- Q 5.12: I'm entering valid capture filters, but I still get "parse error"
- errors.
+ Q 7.8: I'm entering valid capture filters; why do I still get "parse error"
+ errors?
A: There is a bug in some versions of libpcap/WinPcap that cause it to
report parse errors even for valid expressions if a previous filter
you will need to un-install WinPcap and then download and install WinPcap
2.3.
- Q 5.13: I saved a filter and tried to use its name to filter the display,
- but I got an "Unexpected end of filter string" error.
-
- A: You cannot use the name of a saved display filter as a filter. To filter
- the display, you can enter a display filter expression - not the name of a
- saved display filter - in the "Filter:" box at the bottom of the display,
- and type the key or press the "Apply" button (that does not require you to
- have a saved filter), or, if you want to use a saved filter, you can press
- the "Filter:" button, select the filter in the dialog box that pops up, and
- press the "OK" button.
-
- Q 5.14: Why am I seeing lots of packets with incorrect TCP checksums?
+ Q 7.9: How can I capture packets with CRC errors?
- A: If the packets that have incorrect TCP checksums are all being sent by
- the machine on which Ethereal is running, this is probably because the
- network interface on which you're capturing does TCP checksum offloading.
- That means that the TCP checksum is added to the packet by the network
- interface, not by the OS's TCP/IP stack; when capturing on an interface,
- packets being sent by the host on which you're capturing are directly handed
- to the capture interface by the OS, which means that they are handed to the
- capture interface without a TCP checksum being added to them.
+ A: Ethereal can capture only the packets that the packet capture library -
+ libpcap on UNIX-flavored OSes, and the WinPcap port to Windows of libpcap on
+ Windows - can capture, and libpcap/WinPcap can capture only the packets that
+ the OS's raw packet capture mechanism (or the WinPcap driver, and the
+ underlying OS networking code and network interface drivers, on Windows)
+ will allow it to capture.
- The only way to prevent this from happening would be to disable TCP checksum
- offloading, but
- 1. that might not even be possible on some OSes;
- 2. that could reduce networking performance significantly.
+ Unless the OS always supplies packets with errors such as invalid CRCs to
+ the raw packet capture mechanism, or can be configured to do so, invalid
+ CRCs to the raw packet capture mechanism, Ethereal - and other programs that
+ capture raw packets, such as tcpdump - cannot capture those packets. You
+ will have to determine whether your OS needs to be so configured and, if so,
+ can be so configured, configure it if necessary and possible, and make
+ whatever changes to libpcap and the packet capture program you're using are
+ necessary, if any, to support capturing those packets.
- However, you can disable the check that Ethereal does of the TCP checksum,
- so that it won't report any packets as having TCP checksum errors, and so
- that it won't refuse to do TCP reassembly due to a packet having an
- incorrect TCP checksum. That can be set as an Ethereal preference by
- selecting "Preferences" from the "Edit" menu, opening up the "Protocols"
- list in the left-hand pane of the "Preferences" dialog box, selecting "TCP",
- from that list, turning off the "Check the validity of the TCP checksum when
- possible" option, clicking "Save" if you want to save that setting in your
- preference file, and clicking "OK".
+ Most OSes probably do not support capturing packets with invalid CRCs on
+ Ethernet, and probably do not support it on most other link-layer types.
+ Some drivers on some OSes do support it, such as some Ethernet drivers on
+ FreeBSD; in those OSes, you might always get those packets, or you might
+ only get them if you capture in promiscuous mode (you'd have to determine
+ which is the case).
- It can also be set on the Ethereal or Tethereal command line with a -o
- tcp.check_checksum:false command-line flag, or manually set in your
- preferences file by adding a tcp.check_checksum:false line.
+ Note that libpcap does not currently supply to programs that use it an
+ indication of whether the packet's CRC was invalid (because the drivers
+ themselves do not supply that information to the raw packet capture
+ mechanism); therefore, Ethereal will not indicate which packets had CRC
+ errors unless the FCS was captured (see the next question) and you're using
+ Ethereal 0.9.15 and later, in which case Ethereal will check the CRC and
+ indicate whether it's correct or not.
- Q 5.15: I've just installed Ethereal, and the traffic on my local LAN is
- boring.
+ Q 7.10: How can I capture entire frames, including the FCS?
- A: We have a collection of strange and exotic sample capture files at
- http://wiki.ethereal.com/SampleCaptures
+ A: Ethereal can only capture data that the packet capture library - libpcap
+ on UNIX-flavored OSes, and the WinPcap port to Windows of libpcap on Windows
+ - can capture, and libpcap/WinPcap can capture only the data that the OS's
+ raw packet capture mechanism (or the WinPcap driver, and the underlying OS
+ networking code and network interface drivers, on Windows) will allow it to
+ capture.
- Q 5.16: When I run Ethereal on Solaris 8, it dies with a Bus Error when I
- start it.
+ For any particular link-layer network type, unless the OS supplies the FCS
+ of a frame as part of the frame, or can be configured to do so, Ethereal -
+ and other programs that capture raw packets, such as tcpdump - cannot
+ capture the FCS of a frame. You will have to determine whether your OS needs
+ to be so configured and, if so, can be so configured, configure it if
+ necessary and possible, and make whatever changes to libpcap and the packet
+ capture program you're using are necessary, if any, to support capturing the
+ FCS of a frame.
- A: Some versions of the GTK+ library from www.sunfreeware.org appear to be
- buggy, causing Ethereal to drop core with a Bus Error. Un-install those
- packages, and try getting the 1.2.10 version from that site, or the version
- from The Written Word, or the version from Sun's GNOME distribution, or the
- version from the supplemental software CD that comes with the Solaris media
- kit, or build it from source from the GTK Web site. Update the GLib library
- to the 1.2.10 version, from the same source, as well. (If you get the 1.2.10
- versions from www.sunfreeware.org, and the problem persists, un-install them
- and try installing one of the other versions mentioned.)
+ Most OSes do not support capturing the FCS of a frame on Ethernet, and
+ probably do not support it on most other link-layer types. Some drivres on
+ some OSes do support it, such as some (all?) Ethernet drivers on NetBSD and
+ possibly the driver for Apple's gigabit Ethernet interface in Mac OS X; in
+ those OSes, you might always get the FCS, or you might only get the FCS if
+ you capture in promiscuous mode (you'd have to determine which is the case).
- Similar problems may exist with older versions of GTK+ for earlier versions
- of Solaris.
+ Versions of Ethereal prior to 0.9.15 will not treat an Ethernet FCS in a
+ captured packet as an FCS. 0.9.15 and later will attempt to determine
+ whether there's an FCS at the end of the frame and, if it thinks there is,
+ will display it as such, and will check whether it's the correct CRC-32
+ value or not.
- Q 5.17: When I run Ethereal, I get an error
+ Q 7.11: I'm capturing packets on a machine on a VLAN; why don't the packets
+ I'm capturing have VLAN tags?
- Gtk-CRITICAL **: file gtkwindow.c: line 3107 (gtk_window_resize):
- assertion `height > 0' failed.
+ A: You might be capturing on what might be called a "VLAN interface" - the
+ way a particular OS makes VLANs plug into the networking stack might, for
+ example, be to have a network device object for the physical interface,
+ which takes VLAN packets, strips off the VLAN header and constructs an
+ Ethernet header, and passes that packet to an internal network device object
+ for the VLAN, which then passes the packets onto various higher-level
+ protocol implementations.
- A: This is a bug in Ethereal 0.10.5 and 0.10.5a, which is fixed in Ethereal
- 0.10.6 and later releases.
+ In order to see the raw Ethernet packets, rather than "de-VLANized" packets,
+ you would have to capture not on the virtual interface for the VLAN, but on
+ the interface corresponding to the physical network device, if possible. See
+ the Ethereal Wiki item on VLAN capturing for details.
- Q 5.18: When I run Tethereal with the "-x" option, it crashes with an error
+ Q 7.12: Why does Ethereal hang after I stop a capture?
- "** ERROR **: file print.c: line 691 (print_line): should not be reached.
+ A: The most likely reason for this is that Ethereal is trying to look up an
+ IP address in the capture to convert it to a name (so that, for example, it
+ can display the name in the source address or destination address columns),
+ and that lookup process is taking a very long time.
- A: This is a bug in Ethereal 0.10.0a, which is fixed in 0.10.1 and later
- releases. To work around the bug, don't use "-x" unless you're also using
- "-V"; note that "-V" produces a full dissection of each packet, so you might
- not want to use it.
+ Ethereal calls a routine in the OS of the machine on which it's running to
+ convert of IP addresses to the corresponding names. That routine probably
+ does one or more of:
+ * a search of a system file listing IP addresses and names;
+ * a lookup using DNS;
+ * on UNIX systems, a lookup using NIS;
+ * on Windows systems, a NetBIOS-over-TCP query.
- Q 5.19: When I run Ethereal on Windows NT, it dies with a Dr. Watson error,
- reporting an "Integer division by zero" exception, when I start it.
+ If a DNS server that's used in an address lookup is not responding, the
+ lookup will fail, but will only fail after a timeout while the system
+ routine waits for a reply.
- A: In at least some case, this appears to be due to using the default VGA
- driver; if that's not the correct driver for your video card, try running
- the correct driver for your video card.
+ In addition, on Windows systems, if the DNS lookup of the address fails,
+ either because the server isn't responding or because there are no records
+ in the DNS that could be used to map the address to a name, a
+ NetBIOS-over-TCP query will be made. That query involves sending a message
+ to the NetBIOS-over-TCP name service on that machine, asking for the name
+ and other information about the machine. If the machine isn't running
+ software that responds to those queries - for example, many non-Windows
+ machines wouldn't be running that software - the lookup will only fail after
+ a timeout. Those timeouts can cause the lookup to take a long time.
- Q 5.20: When I try to run Ethereal, it complains about sprint_realloc_objid
- being undefined.
+ If you disable network address-to-name translation - for example, by turning
+ off the "Enable network name resolution" option in the "Capture Options"
+ dialog box for starting a network capture - the lookups of the address won't
+ be done, which may speed up the process of reading the capture file after
+ the capture is stopped. You can make that setting the default by selecting
+ "Preferences" from the "Edit" menu, turning off the "Enable network name
+ resolution" option in the "Name resolution" options in the preferences
+ disalog box, and using the "Save" button in that dialog box; note that this
+ will save all your current preference settings.
- A: Ethereal can only be linked with version 4.2.2 or later of UCD SNMP. Your
- version of Ethereal was dynamically linked with such a version of UCD SNMP;
- however, you have an older version of UCD SNMP installed, which means that
- when Ethereal is run, it tries to link to the older version, and fails. You
- will have to replace that version of UCD SNMP with version 4.2.2 or a later
- version.
+ If Ethereal hangs when reading a capture even with network name resolution
+ turned off, there might, for example, be a bug in one of Ethereal's
+ dissectors for a protocol causing it to loop infinitely. If you're not
+ running the most recent release of Ethereal, you should first upgrade to
+ that release, as, if there's a bug of that sort, it might've been fixed in a
+ release after the one you're running. If the hang occurs in the most recent
+ release of Ethereal, the bug should be reported to the Ethereal developers'
+ mailing list at ethereal-dev@ethereal.com.
- Q 5.21: I'm running Ethereal on Linux; why do my time stamps have only 100ms
- resolution, rather than 1us resolution?
+ On UNIX-flavored OSes, please try to force Ethereal to dump core, by sending
+ it a SIGABRT signal (usually signal 6) with the kill command, and then get a
+ stack trace if you have a debugger installed. A stack trace can be obtained
+ by using your debugger (gdb in this example), the Ethereal binary, and the
+ resulting core file. Here's an example of how to use the gdb command
+ backtrace to do so.
+ $ gdb ethereal core
+ (gdb) backtrace
+ ..... prints the stack trace
+ (gdb) quit
+ $
- A: Ethereal gets time stamps from libpcap/WinPcap, and libpcap/WinPcap get
- them from the OS kernel, so Ethereal - and any other program using libpcap,
- such as tcpdump - is at the mercy of the time stamping code in the OS for
- time stamps.
+ The core dump file may be named "ethereal.core" rather than "core" on some
+ platforms (e.g., BSD systems).
- At least on x86-based machines, Linux can get high-resolution time stamps on
- newer processors with the Time Stamp Counter (TSC) register; for example,
- Intel x86 processors, starting with the Pentium Pro, and including all x86
- processors since then, have had a TSC, and other vendors probably added the
- TSC at some point to their families of x86 processors.
+ Also, if at all possible, please send a copy of the capture file that caused
+ the problem; when capturing packets, Ethereal normally writes captured
+ packets to a temporary file, which will probably be in /tmp or /var/tmp on
+ UNIX-flavored OSes, \TEMP on the main system disk (normally C:) on Windows
+ 9x/Me/NT 4.0, and \Documents and Settings\your login name\Local
+ Settings\Temp on the main system disk on Windows 2000/Windows XP/Windows
+ Server 2003, so the capture file will probably be there. It will have a name
+ beginning with ether, with some mixture of letters and numbers after that.
+ Please don't send a trace file greater than 1 MB when compressed; instead,
+ make it available via FTP or HTTP, or say it's available but leave it up to
+ a developer to ask for it. If the trace file contains sensitive information
+ (e.g., passwords), then please do not send it.
- The Linux kernel must be configured with the CONFIG_X86_TSC option enabled
- in order to use the TSC. Make sure this option is enabled in your kernel.
+8. Capturing packets on Windows
- In addition, some Linux distributions may have bugs in their versions of the
- kernel that cause packets not to be given high-resolution time stamps even
- if the TSC is enabled. See, for example, bug 61111 for Red Hat Linux 7.2. If
- your distribution has a bug such as this, you may have to run a standard
- kernel from kernel.org in order to get high-resolution time stamps.
+ Q 8.1: I'm running Ethereal on Windows; why does some network interface on
+ my machine not show up in the list of interfaces in the "Interface:" field
+ in the dialog box popped up by "Capture->Start", and/or why does Ethereal
+ give me an error if I try to capture on that interface?
- Q 5.22: I'm capturing packets on {Windows 95, Windows 98, Windows Me}; why
- are the time stamps on packets wrong?
+ A: If you are running Ethereal on Windows NT 4.0, Windows 2000, Windows XP,
+ or Windows Server 2003, and this is the first time you have run a
+ WinPcap-based program (such as Ethereal, or Tethereal, or WinDump, or
+ Analyzer, or...) since the machine was rebooted, you need to run that
+ program from an account with administrator privileges; once you have run
+ such a program, you will not need administrator privileges to run any such
+ programs until you reboot.
- A: This is due to a bug in WinPcap. The bug should be fixed in WinPcap 3.0.
+ If you are running on Windows 95/98/Me, or if you are running on Windows NT
+ 4.0/Windows 2000/Windows XP/Windows Server 2003 and have administrator
+ privileges or a WinPcap-based program has been run with those privileges
+ since the machine rebooted, this problem might clear up if you completely
+ un-install WinPcap and then re-install it.
- Q 5.23: When I try to run Ethereal on Windows, it fails to run because it
- can't find packet.dll.
+ If that doesn't work, then note that Ethereal relies on the WinPcap library,
+ on the WinPcap device driver, and on the facilities that come with the OS on
+ which it's running in order to do captures.
- A: In older versions of Ethereal, there were two binary distributions
- available for Windows, one that supported capturing packets, and one that
- didn't. The version that supported capturing packets required that you
- install the WinPcap driver; if you didn't install it, it would fail to run
- because it couldn't find packet.dll.
+ Therefore, if the OS, the WinPcap library, or the WinPcap driver don't
+ support capturing on a particular network interface device, Ethereal won't
+ be able to capture on that device.
- The current version of Ethereal has only one binary distribution for
- Windows; that version will check whether WinPcap is installed and, if it's
- not, will disable support for packet capture.
+ Note that:
+ 1. 2.02 and earlier versions of the WinPcap driver and library that
+ Ethereal uses for packet capture didn't support Token Ring interfaces;
+ versions 2.1 and later support Token Ring, and the current version of
+ Ethereal works with (and, in fact, requires) WinPcap 2.1 or later.
+ If you are having problems capturing on Token Ring interfaces, and you
+ have WinPcap 2.02 or an earlier version of WinPcap installed, you should
+ uninstall WinPcap, download and install the current version of WinPcap,
+ and then install the latest version of Ethereal.
+ 2. On Windows 95, 98, or Me, sometimes more than one interface will be
+ given the same name; if that is the case, you will only be able to
+ capture on one of those interfaces - it's not clear to which one the
+ name, when used in a WinPcap-based application, will refer. For example,
+ if you have a PPP serial interface and a VPN interface, they might show
+ up with the same name, for example "ppp-mac", and if you try to capture
+ on "ppp-mac", it might not capture on the interface you're currently
+ using. In that case, you might, for example, have to remove the VPN
+ interface from the system in order to capture on the PPP serial
+ interface.
+ 3. WinPcap 2.3 has problems supporting PPP WAN interfaces on Windows NT
+ 4.0, Windows 2000, Windows XP, and Windows Server 2003, and, to avoid
+ those problems, support for PPP WAN interfaces on those versions of
+ Windows has been disabled in WinPcap 3.0. Regular dial-up lines, ISDN
+ lines, ADSL connections using PPPoE or PPPoA, and various other lines
+ such as T1/E1 lines are all PPP interfaces, so those interfaces might
+ not show up on the list of interfaces in the "Capture Options" dialog on
+ those OSes.
+ On Windows 2000, Windows XP, and Windows Server 2003, but not Windows NT
+ 4.0 or Windows Vista Beta 1, you should be able to capture on the
+ "GenericDialupAdapter" with WinPcap 3.1. (3.1 beta releases called it
+ the "NdisWanAdapter"; if you're using a 3.1 beta release, you should
+ un-install it and install the final 3.1 release.) See the Ethereal Wiki
+ item on PPP capturing for details.
+ 4. WinPcap prior to 3.0 does not support multiprocessor machines (note that
+ machines with a single multi-threaded processor, such as Intel's new
+ multi-threaded x86 processors, are multiprocessor machines as far as the
+ OS and WinPcap are concerned), and recent 2.x versions of WinPcap refuse
+ to operate if they detect that they're running on a multiprocessor
+ machine, which means that they may not show any network interfaces. You
+ will need to use WinPcap 3.0 to capture on a multiprocessor machine.
- The WinPcap driver and libraries can be downloaded from the WinPcap Web
- site, the local mirror of the WinPcap Web site, or the Wiretapped.net mirror
- of the WinPcap site.
+ If an interface doesn't show up in the list of interfaces in the
+ "Interface:" field, and you know the name of the interface, try entering
+ that name in the "Interface:" field and capturing on that device.
+
+ If the attempt to capture on it succeeds, the interface is somehow not being
+ reported by the mechanism Ethereal uses to get a list of interfaces. Try
+ listing the interfaces with WinDump; see the WinDump Web site or the local
+ mirror of the WinDump Web site for information on using WinDump.
- Q 5.24: I'm running Ethereal on Windows NT 4.0/Windows 2000/Windows
+ You would run WinDump with the -D flag; if it lists the interface, please
+ report this to ethereal-dev@ethereal.com giving full details of the problem,
+ including
+ * the operating system you're using, and the version of that operating
+ system;
+ * the type of network device you're using;
+ * the output of WinDump.
+
+ If WinDump does not list the interface, this is almost certainly a problem
+ with one or more of:
+ * the operating system you're using;
+ * the device driver for the interface you're using;
+ * the WinPcap library and/or the WinPcap device driver;
+
+ so first check the WinPcap FAQ, the local mirror of that FAQ, or the
+ Wiretapped.net mirror of that FAQ, to see if your problem is mentioned
+ there. If not, then see the WinPcap support page (or the local mirror of
+ that page) - check the "Submitting bugs" section.
+
+ If you are having trouble capturing on a particular network interface, first
+ try capturing on that device with WinDump; see the WinDump Web site or the
+ local mirror of the WinDump Web site for information on using WinDump.
+
+ If you can capture on the interface with WinDump, send mail to
+ ethereal-users@ethereal.com giving full details of the problem, including
+ * the operating system you're using, and the version of that operating
+ system;
+ * the type of network device you're using;
+ * the error message you get from Ethereal.
+
+ If you cannot capture on the interface with WinDump, this is almost
+ certainly a problem with one or more of:
+ * the operating system you're using;
+ * the device driver for the interface you're using;
+ * the WinPcap library and/or the WinPcap device driver;
+
+ so first check the WinPcap FAQ, the local mirror of that FAQ, or the
+ Wiretapped.net mirror of that FAQ, to see if your problem is mentioned
+ there. If not, then see the WinPcap support page (or the local mirror of
+ that page) - check the "Submitting bugs" section.
+
+ You may also want to ask the ethereal-users@ethereal.com and the
+ winpcap-users@winpcap.org mailing lists to see if anybody happens to know
+ about the problem and know a workaround or fix for the problem. (Note that
+ you will have to subscribe to that list in order to be allowed to mail to
+ it; see the WinPcap support page, or the local mirror of that page, for
+ information on the mailing list.) In your mail, please give full details of
+ the problem, as described above, and also indicate that the problem occurs
+ with WinDump, not just with Ethereal.
+
+ Q 8.2: I'm running Ethereal on Windows; why do no network interfaces show up
+ in the list of interfaces in the "Interface:" field in the dialog box popped
+ up by "Capture->Start"?
+
+ A: This is really the same question as the previous one; see the response to
+ that question.
+
+ Q 8.3: I'm running Ethereal on Windows; why doesn't my serial port/ADSL
+ modem/ISDN modem show up in the list of interfaces in the "Interface:" field
+ in the dialog box popped up by "Capture->Start"?
+
+ A: Internet access on those devices is often done with the Point-to-Point
+ (PPP) protocol; WinPcap 2.3 has problems supporting PPP WAN interfaces on
+ Windows NT 4.0, Windows 2000, Windows XP, and Windows Server 2003, and, to
+ avoid those problems, support for PPP WAN interfaces on those versions of
+ Windows has been disabled in WinPcap 3.0.
+
+ On Windows 2000, Windows XP, and Windows Server 2003, but not Windows NT 4.0
+ or Windows Vista Beta 1, you should be able to capture on the
+ "GenericDialupAdapter" with WinPcap 3.1. (3.1 beta releases called it the
+ "NdisWanAdapter"; if you're using a 3.1 beta release, you should un-install
+ it and install the final 3.1 release.) See the Ethereal Wiki item on PPP
+ capturing for details.
+
+ Q 8.4: I'm running Ethereal on Windows NT 4.0/Windows 2000/Windows
XP/Windows Server 2003; my machine has a PPP (dial-up POTS, ISDN, etc.)
interface, and it shows up in the "Interface" item in the "Capture Options"
dialog box. Why can no packets be sent on or received from that network
"Capture Preferences" dialog box, but this may mean that outgoing packets,
or incoming packets, won't be seen in the capture.
- On Windows 2000 and later, installing the beta version of WinPcap 3.1 might
- help, although, as it's a beta version, that might cause some other problems
- that don't occur with older versions of WinPcap; you should report those
- problems to the WinPcap developers, so that they can try to fix those
- problems before the final version of WinPcap 3.1 is released. WinPcap 3.1
- will not support PPP captures on Windows NT 4.0. See the Ethereal Wiki item
- on PPP capturing for details.
+ On Windows 2000, Windows XP, and Windows Server 2003, but not Windows NT 4.0
+ or Windows Vista Beta 1, you should be able to capture on the
+ "GenericDialupAdapter" with WinPcap 3.1. (3.1 beta releases called it the
+ "NdisWanAdapter"; if you're using a 3.1 beta release, you should un-install
+ it and install the final 3.1 release.) See the Ethereal Wiki item on PPP
+ capturing for details.
- Q 5.25: I'm running Ethereal on Windows 95/98/Me, on a machine with more
- than one network adapter of the same type; Ethereal shows all of those
- adapters with the same name, but I can't use any of those adapters other
- than the first one.
+ Q 8.5: I'm running Ethereal on Windows 95/98/Me, on a machine with more than
+ one network adapter of the same type; why does Ethereal show all of those
+ adapters with the same name, not letting me use any of those adapters other
+ than the first one?
A: Unfortunately, Windows 95/98/Me gives the same name to multiple instances
of the type of same network adapter. Therefore, WinPcap cannot distinguish
between them, so a WinPcap-based application can capture only on the first
such interface; Ethereal is a libpcap/WinPcap-based application.
- Q 5.26: I'm running Ethereal on Windows, and I'm not seeing any traffic
- being sent by the machine running Ethereal.
+ Q 8.6: I'm running Ethereal on Windows; why am I not seeing any traffic
+ being sent by the machine running Ethereal?
A: If you are running some form of VPN client software, it might be causing
this problem; people have seen this problem when they have Check Point's VPN
outgoing packets are delivered to the software that requested that the
interface run promiscuously; try turning promiscuous mode off.
- Q 5.27: I'm trying to capture traffic but I'm not seeing any.
+ Q 8.7: When I capture on Windows in promiscuous mode, I can see packets
+ other than those sent to or from my machine; however, those packets show up
+ with a "Short Frame" indication, unlike packets to or from my machine. What
+ should I do to arrange that I see those packets in their entirety?
- A: Is the machine running Ethereal sending out any traffic on the network
- interface on which you're capturing, or receiving any traffic on that
- network, or is there any broadcast traffic on the network or multicast
- traffic to a multicast group to which the machine running Ethereal belongs?
+ A: In at least some cases, this appears to be the result of PGPnet running
+ on the network interface on which you're capturing; turn it off on that
+ interface.
- If not, this may just be a problem with promiscuous sniffing, either due to
- running on a switched network or a dual-speed hub, or due to problems with
- the interface not supporting promiscuous mode; see the response to this
- earlier question.
+ Q 8.8: I'm capturing packets on {Windows 95, Windows 98, Windows Me}; why
+ are the time stamps on packets wrong?
- Otherwise, on Windows, see the response to this question and, on a
- UNIX-flavored OS, see the response to this question.
+ A: This is due to a bug in WinPcap. The bug should be fixed in WinPcap 3.0
+ and later releases.
- Q 5.28: I have an XXX network card on my machine; if I try to capture on it,
- my machine crashes or resets itself.
+ Q 8.9: I'm trying to capture 802.11 traffic on Windows; why am I not seeing
+ any packets?
- A: This is almost certainly a problem with one or more of:
- * the operating system you're using;
- * the device driver for the interface you're using;
- * the libpcap/WinPcap library and, if this is Windows, the WinPcap device
- driver;
+ A: At least some 802.11 card drivers on Windows appear not to see any
+ packets if they're running in promiscuous mode. Try turning promiscuous mode
+ off; you'll only be able to see packets sent by and received by your
+ machine, not third-party traffic, and it'll look like Ethernet traffic and
+ won't include any management or control frames, but that's a limitation of
+ the card drivers.
- so:
- * if you are using Windows, see the WinPcap support page (or the local
- mirror of that page) - check the "Submitting bugs" section;
- * if you are using some Linux distribution, some version of BSD, or some
- other UNIX-flavored OS, you should report the problem to the company or
- organization that produces the OS (in the case of a Linux distribution,
- report the problem to whoever produces the distribution).
+ See MicroLogix's list of cards supported with WinPcap for information on
+ support of various adapters and drivers with WinPcap.
- Q 5.29: My machine crashes or resets itself when I select "Start" from the
- "Capture" menu or select "Preferences" from the "Edit" menu.
+ Q 8.10: I'm trying to capture 802.11 traffic on Windows; why am I seeing
+ packets received by the machine on which I'm capturing traffic, but not
+ packets sent by that machine?
- A: Both of those operations cause Ethereal to try to build a list of the
- interfaces that it can open; it does so by getting a list of interfaces and
- trying to open them. There is probably an OS, driver, or, for Windows,
- WinPcap bug that causes the system to crash when this happens; see the
- previous question.
+ A: This appears to be another problem with promiscuous mode; try turning it
+ off.
- Q 5.30: Does Ethereal work on Windows Me?
+ Q 8.11: I'm trying to capture Ethernet VLAN traffic on Windows, and I'm
+ capturing on a "raw" Ethernet device rather than a "VLAN interface", so that
+ I can see the VLAN headers; why am I seeing packets received by the machine
+ on which I'm capturing traffic, but not packets sent by that machine?
- A: Yes, but if you want to capture packets, you will need to install the
- latest version of WinPcap, as 2.02 and earlier versions of WinPcap didn't
- support Windows Me. You should also install the latest version of Ethereal
- as well.
+ A: The way the Windows networking code works probably means that packets are
+ sent on a "VLAN interface" rather than the "raw" device, so packets sent by
+ the machine will only be seen when you capture on the "VLAN interface". If
+ so, you will be unable to see outgoing packets when capturing on the "raw"
+ device, so you are stuck with a choice between seeing VLAN headers and
+ seeing outgoing packets.
- Q 5.31: Does Ethereal work on Windows XP?
+9. Capturing packets on UN*Xes
- A: Yes, but if you want to capture packets, you will need to install the
- latest version of WinPcap, as 2.2 and earlier versions of WinPcap didn't
- support Windows XP.
+ Q 9.1: I'm running Ethereal on a UNIX-flavored OS; why does some network
+ interface on my machine not show up in the list of interfaces in the
+ "Interface:" field in the dialog box popped up by "Capture->Start", and/or
+ why does Ethereal give me an error if I try to capture on that interface?
- Q 5.32: Why doesn't Ethereal correctly identify RTP packets? It shows them
- only as UDP.
+ A: You may need to run Ethereal from an account with sufficient privileges
+ to capture packets, such as the super-user account, or may need to give your
+ account sufficient privileges to capture packets. Only those interfaces that
+ Ethereal can open for capturing show up in that list; if you don't have
+ sufficient privileges to capture on any interfaces, no interfaces will show
+ up in the list. See the Ethereal Wiki item on capture privileges for details
+ on how to give a particular account or account group capture privileges on
+ platforms where that can be done.
- A: Ethereal can identify a UDP datagram as containing a packet of a
- particular protocol running atop UDP only if
- 1. The protocol in question has a particular standard port number, and the
- UDP source or destination port number is that port
- 2. Packets of that protocol can be identified by looking for a "signature"
- of some type in the packet - i.e., some data that, if Ethereal finds it
- in some particular part of a packet, means that the packet is almost
- certainly a packet of that type.
- 3. Some other traffic earlier in the capture indicated that, for example,
- UDP traffic between two particular addresses and ports will be RTP
- traffic.
+ If you are running Ethereal from an account with sufficient privileges, then
+ note that Ethereal relies on the libpcap library, and on the facilities that
+ come with the OS on which it's running in order to do captures. On some
+ OSes, those facilities aren't present by default; see the Ethereal Wiki item
+ on adding capture support for details.
- RTP doesn't have a standard port number, so 1) doesn't work; it doesn't, as
- far as I know, have any "signature", so 2) doesn't work.
+ And, even if you're running with an account that has sufficient privileges
+ to capture, and capture support is present in your OS, if the OS or the
+ libpcap library don't support capturing on a particular network interface
+ device or particular types of devices, Ethereal won't be able to capture on
+ that device.
- That leaves 3). If there's RTSP traffic that sets up an RTP session, then,
- at least in some cases, the RTSP dissector will set things up so that
- subsequent RTP traffic will be identified. Currently, that's the only place
- we do that; there may be other places.
+ On Solaris, note that libpcap 0.6.2 and earlier didn't support Token Ring
+ interfaces; the current version, 0.7.2, does support Token Ring, and the
+ current version of Ethereal works with libcap 0.7.2 and later.
- However, there will always be places where Ethereal is simply incapable of
- deducing that a given UDP flow is RTP; a mechanism would be needed to allow
- the user to specify that a given conversation should be treated as RTP. As
- of Ethereal 0.8.16, such a mechanism exists; if you select a UDP or TCP
- packet, the right mouse button menu will have a "Decode As..." menu item,
- which will pop up a dialog box letting you specify that the source port, the
- destination port, or both the source and destination ports of the packet
- should be dissected as some particular protocol.
+ If an interface doesn't show up in the list of interfaces in the
+ "Interface:" field, and you know the name of the interface, try entering
+ that name in the "Interface:" field and capturing on that device.
- Q 5.33: Why doesn't Ethereal show Yahoo Messenger packets in captures that
- contain Yahoo Messenger traffic?
+ If the attempt to capture on it succeeds, the interface is somehow not being
+ reported by the mechanism Ethereal uses to get a list of interfaces; please
+ report this to ethereal-dev@ethereal.com giving full details of the problem,
+ including
+ * the operating system you're using, and the version of that operating
+ system (for Linux, give both the version number of the kernel and the
+ name and version number of the distribution you're using);
+ * the type of network device you're using.
- A: Ethereal only recognizes as Yahoo Messenger traffic packets to or from
- TCP port 3050 that begin with "YPNS", "YHOO", or "YMSG". TCP segments that
- start with the middle of a Yahoo Messenger packet that takes more than one
- TCP segment will not be recognized as Yahoo Messenger packets (even if the
- TCP segment also contains the beginning of another Yahoo Messenger packet).
+ If you are having trouble capturing on a particular network interface, and
+ you've made sure that (on platforms that require it) you've arranged that
+ packet capture support is present, as per the above, first try capturing on
+ that device with tcpdump.
+
+ If you can capture on the interface with tcpdump, send mail to
+ ethereal-users@ethereal.com giving full details of the problem, including
+ * the operating system you're using, and the version of that operating
+ system (for Linux, give both the version number of the kernel and the
+ name and version number of the distribution you're using);
+ * the type of network device you're using;
+ * the error message you get from Ethereal.
- Q 5.34: Why do I get the error
+ If you cannot capture on the interface with tcpdump, this is almost
+ certainly a problem with one or more of:
+ * the operating system you're using;
+ * the device driver for the interface you're using;
+ * the libpcap library;
- Gdk-ERROR **: Palettized display (256-colour) mode not supported on
- Windows.
- aborting....
+ so you should report the problem to the company or organization that
+ produces the OS (in the case of a Linux distribution, report the problem to
+ whoever produces the distribution).
- when I try to run Ethereal on Windows?
+ You may also want to ask the ethereal-users@ethereal.com and the
+ tcpdump-workers@tcpdump.org mailing lists to see if anybody happens to know
+ about the problem and know a workaround or fix for the problem. In your
+ mail, please give full details of the problem, as described above, and also
+ indicate that the problem occurs with tcpdump not just with Ethereal.
- A: Ethereal is built using the GTK+ toolkit, which supports most
- UNIX-flavored OSes, and also supports Windows.
+ Q 9.2: I'm running Ethereal on a UNIX-flavored OS; why do no network
+ interfaces show up in the list of interfaces in the "Interface:" field in
+ the dialog box popped up by "Capture->Start"?
- Windows versions of Ethereal before 0.9.14 were built with an older version
- of that toolkit, which didn't support 256-color mode on Windows - it
- required HiColor (16-bit colors) or more.
+ A: This is really the same question as the previous one; see the response to
+ that question.
- Windows versions of Ethereal 0.9.14 and later are built with a version of
- that toolkit that supports 256-color mode; upgrade to the current version of
- Ethereal if you want to run on a display in 256-color mode.
+ Q 9.3: I'm capturing packets on Linux; why do the time stamps have only
+ 100ms resolution, rather than 1us resolution?
- Q 5.35: When I capture on Windows in promiscuous mode, I can see packets
- other than those sent to or from my machine; however, those packets show up
- with a "Short Frame" indication, unlike packets to or from my machine. What
- should I do to arrange that I see those packets in their entirety?
+ A: Ethereal gets time stamps from libpcap/WinPcap, and libpcap/WinPcap get
+ them from the OS kernel, so Ethereal - and any other program using libpcap,
+ such as tcpdump - is at the mercy of the time stamping code in the OS for
+ time stamps.
- A: In at least some cases, this appears to be the result of PGPnet running
- on the network interface on which you're capturing; turn it off on that
- interface.
+ At least on x86-based machines, Linux can get high-resolution time stamps on
+ newer processors with the Time Stamp Counter (TSC) register; for example,
+ Intel x86 processors, starting with the Pentium Pro, and including all x86
+ processors since then, have had a TSC, and other vendors probably added the
+ TSC at some point to their families of x86 processors.
- Q 5.36: I'm capturing packets on a machine on a VLAN; why don't the packets
- I'm capturing have VLAN tags?
+ The Linux kernel must be configured with the CONFIG_X86_TSC option enabled
+ in order to use the TSC. Make sure this option is enabled in your kernel.
- A: You might be capturing on what might be called a "VLAN interface" - the
- way a particular OS makes VLANs plug into the networking stack might, for
- example, be to have a network device object for the physical interface,
- which takes VLAN packets, strips off the VLAN header and constructs an
- Ethernet header, and passes that packet to an internal network device object
- for the VLAN, which then passes the packets onto various higher-level
- protocol implementations.
+ In addition, some Linux distributions may have bugs in their versions of the
+ kernel that cause packets not to be given high-resolution time stamps even
+ if the TSC is enabled. See, for example, bug 61111 for Red Hat Linux 7.2. If
+ your distribution has a bug such as this, you may have to run a standard
+ kernel from kernel.org in order to get high-resolution time stamps.
- In order to see the raw Ethernet packets, rather than "de-VLANized" packets,
- you would have to capture not on the virtual interface for the VLAN, but on
- the interface corresponding to the physical network device, if possible. See
- the Ethereal Wiki item on VLAN capturing for details.
+10. Capturing packets on wireless LANs
- Q 5.37: How can I capture raw 802.11 frames, including non-data (management,
+ Q 10.1: How can I capture raw 802.11 frames, including non-data (management,
beacon) frames?
A: That depends on the operating system on which you're running, and on the
See the Ethereal Wiki item on 802.11 capturing for details.
- Q 5.38: How do I capture on an 802.11 device in monitor mode?
+ Q 10.2: How do I capture on an 802.11 device in monitor mode?
A: Whether you will be able to capture in monitor mode depends on the
operating system, adapter, and driver you're using. See the previous
question for information on monitor mode, including a link to the Ethereal
Wiki page that gives details on 802.11 capturing.
- Q 5.39: I'm trying to capture 802.11 traffic on Windows; why am I not seeing
- any packets?
-
- A: At least some 802.11 card drivers on Windows appear not to see any
- packets if they're running in promiscuous mode. Try turning promiscuous mode
- off; you'll only be able to see packets sent by and received by your
- machine, not third-party traffic, and it'll look like Ethernet traffic and
- won't include any management or control frames, but that's a limitation of
- the card drivers.
-
- See MicroLogix's list of cards supported with WinPcap for information on
- support of various adapters and drivers with WinPcap.
-
- Q 5.40: I'm trying to capture 802.11 traffic on Windows; why am I seeing
- packets received by the machine on which I'm capturing traffic, but not
- packets sent by that machine?
-
- A: This appears to be another problem with promiscuous mode; try turning it
- off.
-
- Q 5.41: How can I capture packets with CRC errors?
-
- A: Ethereal can capture only the packets that the packet capture library -
- libpcap on UNIX-flavored OSes, and the WinPcap port to Windows of libpcap on
- Windows - can capture, and libpcap/WinPcap can capture only the packets that
- the OS's raw packet capture mechanism (or the WinPcap driver, and the
- underlying OS networking code and network interface drivers, on Windows)
- will allow it to capture.
-
- Unless the OS always supplies packets with errors such as invalid CRCs to
- the raw packet capture mechanism, or can be configured to do so, invalid
- CRCs to the raw packet capture mechanism, Ethereal - and other programs that
- capture raw packets, such as tcpdump - cannot capture those packets. You
- will have to determine whether your OS needs to be so configured and, if so,
- can be so configured, configure it if necessary and possible, and make
- whatever changes to libpcap and the packet capture program you're using are
- necessary, if any, to support capturing those packets.
+11. Viewing traffic
- Most OSes probably do not support capturing packets with invalid CRCs on
- Ethernet, and probably do not support it on most other link-layer types.
- Some drivers on some OSes do support it, such as some Ethernet drivers on
- FreeBSD; in those OSes, you might always get those packets, or you might
- only get them if you capture in promiscuous mode (you'd have to determine
- which is the case).
+ Q 11.1: Why am I seeing lots of packets with incorrect TCP checksums?
- Note that libpcap does not currently supply to programs that use it an
- indication of whether the packet's CRC was invalid (because the drivers
- themselves do not supply that information to the raw packet capture
- mechanism); therefore, Ethereal will not indicate which packets had CRC
- errors unless the FCS was captured (see the next question) and you're using
- Ethereal 0.9.15 and later, in which case Ethereal will check the CRC and
- indicate whether it's correct or not.
+ A: If the packets that have incorrect TCP checksums are all being sent by
+ the machine on which Ethereal is running, this is probably because the
+ network interface on which you're capturing does TCP checksum offloading.
+ That means that the TCP checksum is added to the packet by the network
+ interface, not by the OS's TCP/IP stack; when capturing on an interface,
+ packets being sent by the host on which you're capturing are directly handed
+ to the capture interface by the OS, which means that they are handed to the
+ capture interface without a TCP checksum being added to them.
- Q 5.42: How can I capture entire frames, including the FCS?
+ The only way to prevent this from happening would be to disable TCP checksum
+ offloading, but
+ 1. that might not even be possible on some OSes;
+ 2. that could reduce networking performance significantly.
- A: Ethereal can only capture data that the packet capture library - libpcap
- on UNIX-flavored OSes, and the WinPcap port to Windows of libpcap on Windows
- - can capture, and libpcap/WinPcap can capture only the data that the OS's
- raw packet capture mechanism (or the WinPcap driver, and the underlying OS
- networking code and network interface drivers, on Windows) will allow it to
- capture.
+ However, you can disable the check that Ethereal does of the TCP checksum,
+ so that it won't report any packets as having TCP checksum errors, and so
+ that it won't refuse to do TCP reassembly due to a packet having an
+ incorrect TCP checksum. That can be set as an Ethereal preference by
+ selecting "Preferences" from the "Edit" menu, opening up the "Protocols"
+ list in the left-hand pane of the "Preferences" dialog box, selecting "TCP",
+ from that list, turning off the "Check the validity of the TCP checksum when
+ possible" option, clicking "Save" if you want to save that setting in your
+ preference file, and clicking "OK".
- For any particular link-layer network type, unless the OS supplies the FCS
- of a frame as part of the frame, or can be configured to do so, Ethereal -
- and other programs that capture raw packets, such as tcpdump - cannot
- capture the FCS of a frame. You will have to determine whether your OS needs
- to be so configured and, if so, can be so configured, configure it if
- necessary and possible, and make whatever changes to libpcap and the packet
- capture program you're using are necessary, if any, to support capturing the
- FCS of a frame.
+ It can also be set on the Ethereal or Tethereal command line with a -o
+ tcp.check_checksum:false command-line flag, or manually set in your
+ preferences file by adding a tcp.check_checksum:false line.
- Most OSes do not support capturing the FCS of a frame on Ethernet, and
- probably do not support it on most other link-layer types. Some drivres on
- some OSes do support it, such as some (all?) Ethernet drivers on NetBSD and
- possibly the driver for Apple's gigabit Ethernet interface in Mac OS X; in
- those OSes, you might always get the FCS, or you might only get the FCS if
- you capture in promiscuous mode (you'd have to determine which is the case).
+ Q 11.2: I've just installed Ethereal, and the traffic on my local LAN is
+ boring. Where can I find more interesting captures?
- Versions of Ethereal prior to 0.9.15 will not treat an Ethernet FCS in a
- captured packet as an FCS. 0.9.15 and later will attempt to determine
- whether there's an FCS at the end of the frame and, if it thinks there is,
- will display it as such, and will check whether it's the correct CRC-32
- value or not.
+ A: We have a collection of strange and exotic sample capture files at
+ http://wiki.ethereal.com/SampleCaptures
- Q 5.43: Why does Ethereal hang after I stop a capture?
+ Q 11.3: Why doesn't Ethereal correctly identify RTP packets? It shows them
+ only as UDP.
- A: The most likely reason for this is that Ethereal is trying to look up an
- IP address in the capture to convert it to a name (so that, for example, it
- can display the name in the source address or destination address columns),
- and that lookup process is taking a very long time.
+ A: Ethereal can identify a UDP datagram as containing a packet of a
+ particular protocol running atop UDP only if
+ 1. The protocol in question has a particular standard port number, and the
+ UDP source or destination port number is that port
+ 2. Packets of that protocol can be identified by looking for a "signature"
+ of some type in the packet - i.e., some data that, if Ethereal finds it
+ in some particular part of a packet, means that the packet is almost
+ certainly a packet of that type.
+ 3. Some other traffic earlier in the capture indicated that, for example,
+ UDP traffic between two particular addresses and ports will be RTP
+ traffic.
- Ethereal calls a routine in the OS of the machine on which it's running to
- convert of IP addresses to the corresponding names. That routine probably
- does one or more of:
- * a search of a system file listing IP addresses and names;
- * a lookup using DNS;
- * on UNIX systems, a lookup using NIS;
- * on Windows systems, a NetBIOS-over-TCP query.
+ RTP doesn't have a standard port number, so 1) doesn't work; it doesn't, as
+ far as I know, have any "signature", so 2) doesn't work.
- If a DNS server that's used in an address lookup is not responding, the
- lookup will fail, but will only fail after a timeout while the system
- routine waits for a reply.
+ That leaves 3). If there's RTSP traffic that sets up an RTP session, then,
+ at least in some cases, the RTSP dissector will set things up so that
+ subsequent RTP traffic will be identified. Currently, that's the only place
+ we do that; there may be other places.
- In addition, on Windows systems, if the DNS lookup of the address fails,
- either because the server isn't responding or because there are no records
- in the DNS that could be used to map the address to a name, a
- NetBIOS-over-TCP query will be made. That query involves sending a message
- to the NetBIOS-over-TCP name service on that machine, asking for the name
- and other information about the machine. If the machine isn't running
- software that responds to those queries - for example, many non-Windows
- machines wouldn't be running that software - the lookup will only fail after
- a timeout. Those timeouts can cause the lookup to take a long time.
+ However, there will always be places where Ethereal is simply incapable of
+ deducing that a given UDP flow is RTP; a mechanism would be needed to allow
+ the user to specify that a given conversation should be treated as RTP. As
+ of Ethereal 0.8.16, such a mechanism exists; if you select a UDP or TCP
+ packet, the right mouse button menu will have a "Decode As..." menu item,
+ which will pop up a dialog box letting you specify that the source port, the
+ destination port, or both the source and destination ports of the packet
+ should be dissected as some particular protocol.
- If you disable network address-to-name translation - for example, by turning
- off the "Enable network name resolution" option in the "Capture Options"
- dialog box for starting a network capture - the lookups of the address won't
- be done, which may speed up the process of reading the capture file after
- the capture is stopped. You can make that setting the default by selecting
- "Preferences" from the "Edit" menu, turning off the "Enable network name
- resolution" option in the "Name resolution" options in the preferences
- disalog box, and using the "Save" button in that dialog box; note that this
- will save all your current preference settings.
+ Q 11.4: Why doesn't Ethereal show Yahoo Messenger packets in captures that
+ contain Yahoo Messenger traffic?
- If Ethereal hangs when reading a capture even with network name resolution
- turned off, there might, for example, be a bug in one of Ethereal's
- dissectors for a protocol causing it to loop infinitely. If you're not
- running the most recent release of Ethereal, you should first upgrade to
- that release, as, if there's a bug of that sort, it might've been fixed in a
- release after the one you're running. If the hang occurs in the most recent
- release of Ethereal, the bug should be reported to the Ethereal developers'
- mailing list at ethereal-dev@ethereal.com.
+ A: Ethereal only recognizes as Yahoo Messenger traffic packets to or from
+ TCP port 3050 that begin with "YPNS", "YHOO", or "YMSG". TCP segments that
+ start with the middle of a Yahoo Messenger packet that takes more than one
+ TCP segment will not be recognized as Yahoo Messenger packets (even if the
+ TCP segment also contains the beginning of another Yahoo Messenger packet).
- On UNIX-flavored OSes, please try to force Ethereal to dump core, by sending
- it a SIGABRT signal (usually signal 6) with the kill command, and then get a
- stack trace if you have a debugger installed. A stack trace can be obtained
- by using your debugger (gdb in this example), the Ethereal binary, and the
- resulting core file. Here's an example of how to use the gdb command
- backtrace to do so.
- $ gdb ethereal core
- (gdb) backtrace
- ..... prints the stack trace
- (gdb) quit
- $
+12. Filtering traffic
- The core dump file may be named "ethereal.core" rather than "core" on some
- platforms (e.g., BSD systems).
+ Q 12.1: I saved a filter and tried to use its name to filter the display;
+ why do I get an "Unexpected end of filter string" error?
- Also, if at all possible, please send a copy of the capture file that caused
- the problem; when capturing packets, Ethereal normally writes captured
- packets to a temporary file, which will probably be in /tmp or /var/tmp on
- UNIX-flavored OSes, \TEMP on the main system disk (normally C:) on Windows
- 9x/Me/NT 4.0, and \Documents and Settings\your login name\Local
- Settings\Temp on the main system disk on Windows 2000/Windows XP/Windows
- Server 2003, so the capture file will probably be there. It will have a name
- beginning with ether, with some mixture of letters and numbers after that.
- Please don't send a trace file greater than 1 MB when compressed; instead,
- make it available via FTP or HTTP, or say it's available but leave it up to
- a developer to ask for it. If the trace file contains sensitive information
- (e.g., passwords), then please do not send it.
+ A: You cannot use the name of a saved display filter as a filter. To filter
+ the display, you can enter a display filter expression - not the name of a
+ saved display filter - in the "Filter:" box at the bottom of the display,
+ and type the key or press the "Apply" button (that does not require you to
+ have a saved filter), or, if you want to use a saved filter, you can press
+ the "Filter:" button, select the filter in the dialog box that pops up, and
+ press the "OK" button.
- Q 5.44: How can I search for, or filter, packets that have a particular
+ Q 12.2: How can I search for, or filter, packets that have a particular
string anywhere in them?
A: If you want to do this when capturing, you can't. That's a feature that
or byte string fields in the packet; the "contains" operator can also be
used in expressions used to filter the display.
- Q 5.45: How do I filter a capture to see traffic for virus XXX?
+ Q 12.3: How do I filter a capture to see traffic for virus XXX?
A: For some viruses/worms there might be a capture filter to recognize the
virus traffic. Check the CaptureFilters page on the Ethereal Wiki to see if
Please send support questions about Ethereal to the
ethereal-users[AT]ethereal.com mailing list.
For corrections/additions/suggestions for this web page (and not Ethereal
- support questions), please send email to ethereal-web[AT]ethereal.com .
- Last modified: Wed, May 25 2005.
+ support questions), please send email to ethereal-web[AT]ethereal.com.
+ Last modified: Thu, February 23 2006.
+ "Ethereal" and the "e" logo are registered trademarks of Ethereal, Inc.
git.samba.org / obnox / wireshark / wip.git / blobdiff