The Ethereal FAQ
Note: This is just an ASCII snapshot of the faq and may not be up to
- date. Please go to http://www.ethereal.com/faq for the up to
- date version. The version of this snapshot can be found at the
- end of this document.
+ date. Please go to http://www.ethereal.com/faq.html for the up
+ to date version. The version of this snapshot can be found at
+ the end of this document.
INDEX
- General Questions:
+
+General Questions:
1.1 Where can I get help?
- 1.2 What protocols are currently supported?
+ 1.2 How much does Ethereal cost?
+
+ 1.3 Can I use Ethereal commercially?
+
+ 1.4 Can I use Ethereal as part of my commercial product?
+
+ 1.5 What protocols are currently supported?
- 1.3 Are there any plans to support {your favorite protocol}?
+ 1.6 Are there any plans to support {your favorite protocol}?
- 1.4 Can Ethereal read capture files from {your favorite network
+ 1.7 Can Ethereal read capture files from {your favorite network
analyzer}?
- 1.5 What devices can Ethereal use to capture packets?
+ 1.8 What devices can Ethereal use to capture packets?
- 1.6 How do you pronounce Ethereal? Where did the name come from?
+ 1.9 How do you pronounce Ethereal? Where did the name come from?
- Downloading Ethereal:
+Downloading Ethereal:
2.1 I downloaded the Win32 installer, but when I try to run it, I get
an error.
2.2 When I try to download the WinPcap driver and library, I can't get
to the WinPcap Web site.
- Installing Ethereal:
+Installing Ethereal:
3.1 I installed an Ethereal RPM, but Ethereal doesn't seem to be
installed; only Tethereal is installed.
- Building Ethereal:
+Building Ethereal:
4.1 The configure script can't find pcap.h or bpf.h, but I have
libpcap installed.
dftest_DEPENDENCIES was already defined in condition TRUE, which
implies condition HAVE_PLUGINS_TRUE
- when I try to build Ethereal from CVS or a CVS snapshot?
+ when I try to build Ethereal from SVN or a SVN snapshot?
- 4.3 The link failed because of an undefined reference to
- snmp_set_full_objid.
-
- 4.4 The link fails with a number of "Output line too long." messages
+ 4.3 The link fails with a number of "Output line too long." messages
followed by linker errors.
- 4.5 The link fails on Solaris because plugin_list is undefined.
+ 4.4 The link fails on Solaris because plugin_list is undefined.
- 4.6 The build fails on Windows because of conflicts between winsock.h
+ 4.5 The build fails on Windows because of conflicts between winsock.h
and winsock2.h.
- Using Ethereal:
+Using 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.
5.2 I can't see any TCP packets other than packets to and from my
- machine, even though another sniffer on the network sees those
+ machine, even though another analyzer on the network sees those
packets.
- 5.3 I can set a display filter just fine, but capture filters don't
+ 5.3 I'm only seeing ARP packets when I try to capture traffic.
+
+ 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?
+
+ 5.5 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"?
+
+ 5.6 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"?
+
+ 5.7 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?
+
+ 5.8 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"?
+
+ 5.9 Can Ethereal capture on (my T1/E1 line, SS7 links, etc.)?
+
+ 5.10 How do I put an interface into promiscuous mode?
+
+ 5.11 I can set a display filter just fine, but capture filters don't
work.
- 5.4 I'm entering valid capture filters, but I still get "parse error"
+ 5.12 I'm entering valid capture filters, but I still get "parse error"
errors.
- 5.5 I saved a filter and tried to use its name to filter the display,
+ 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.
- 5.6 Why am I seeing lots of packets with incorrect TCP checksums?
+ 5.14 Why am I seeing lots of packets with incorrect TCP checksums?
- 5.7 I've just installed Ethereal, and the traffic on my local LAN is
+ 5.15 I've just installed Ethereal, and the traffic on my local LAN is
boring.
- 5.8 When I run Ethereal on Solaris 8, it dies with a Bus Error when I
+ 5.16 When I run Ethereal on Solaris 8, it dies with a Bus Error when I
start it.
- 5.9 I'm running Ethereal on Linux; why do my time stamps have only
+ 5.17 When I run Ethereal, I get an error
+
+ Gtk-CRITICAL **: file gtkwindow.c: line 3107 (gtk_window_resize):
+ assertion `height > 0' failed.
+
+ 5.18 When I run Tethereal with the "-x" option, it crashes with an
+ error
+
+ "** ERROR **: file print.c: line 691 (print_line): should not be
+ reached.
+
+ 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.
+
+ 5.20 When I try to run Ethereal, it complains about
+ sprint_realloc_objid being undefined.
+
+ 5.21 I'm running Ethereal on Linux; why do my time stamps have only
100ms resolution, rather than 1us resolution?
- 5.10 I'm capturing packets on {Windows 95, Windows 98, Windows Me};
+ 5.22 I'm capturing packets on {Windows 95, Windows 98, Windows Me};
why are the time stamps on packets wrong?
- 5.11 When I try to run Ethereal on Windows, it fails to run because it
+ 5.23 When I try to run Ethereal on Windows, it fails to run because it
can't find packet.dll.
- 5.12 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?
-
- 5.13 I'm running Ethereal on Windows NT/2000/XP/Server; my machine has
+ 5.24 I'm running Ethereal on Windows NT/2000/XP/Server; 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?
- 5.14 I'm running Ethereal on Windows 95/98/Me, on a machine with more
+ 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.
- 5.15 I have an XXX network card on my machine; if I try to capture on
+ 5.26 I'm running Ethereal on Windows, and I'm 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.
+
+ 5.28 I have an XXX network card on my machine; if I try to capture on
it, my machine crashes or resets itself.
- 5.16 My machine crashes or resets itself when I select "Start" from
+ 5.29 My machine crashes or resets itself when I select "Start" from
the "Capture" menu or select "Preferences" from the "Edit" menu.
- 5.17 Does Ethereal work on Windows ME?
+ 5.30 Does Ethereal work on Windows Me?
- 5.18 Does Ethereal work on Windows XP?
+ 5.31 Does Ethereal work on Windows XP?
- 5.19 Why doesn't Ethereal correctly identify RTP packets? It shows
+ 5.32 Why doesn't Ethereal correctly identify RTP packets? It shows
them only as UDP.
- 5.20 Why doesn't Ethereal show Yahoo Messenger packets in captures
+ 5.33 Why doesn't Ethereal show Yahoo Messenger packets in captures
that contain Yahoo Messenger traffic?
- 5.21 Why do I get the error
+ 5.34 Why do I get the error
Gdk-ERROR **: Palettized display (256-colour) mode not supported on
Windows.
when I try to run Ethereal on Windows?
- 5.22 When I capture on Windows in promiscuous mode, I can see packets
+ 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?
- 5.23 How can I capture raw 802.11 packets, including non-data
+ 5.36 I'm capturing packets on a machine on a VLAN; why don't the
+ packets I'm capturing have VLAN tags?
+
+ 5.37 How can I capture raw 802.11 packets, including non-data
(management, beacon) packets?
- 5.24 How can I capture packets with CRC errors?
+ 5.38 How do I capture on an 802.11 device in monitor mode on Linux?
+
+ 5.39 How do I capture on an 802.11 device in monitor mode on FreeBSD?
+
+ 5.40 How do I capture on an 802.11 device in monitor mode on NetBSD?
+
+ 5.41 I'm trying to capture 802.11 traffic on Windows; why am I not
+ seeing any packets?
+
+ 5.42 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?
- 5.25 How can I capture entire frames, including the FCS?
+ 5.43 How can I capture packets with CRC errors?
- 5.26 Ethereal hangs after I stop a capture.
+ 5.44 How can I capture entire frames, including the FCS?
- 5.27 How can I search for, or filter, packets that have a particular
+ 5.45 Ethereal hangs after I stop a capture.
+
+ 5.46 How can I search for, or filter, packets that have a particular
string anywhere in them?
- GENERAL QUESTIONS
+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
- Q 1.2: What protocols are currently supported?
+ Q 1.2: How much does Ethereal cost?
+
+ A: Ethereal is "free software"; you can download it without paying any
+ license fee. The version of Ethereal you download isn't a "demo"
+ version, with limitations not present in a "full" version; it is the
+ full version.
+
+ The license under which Ethereal is issued is the GNU General Public
+ License. See the GNU GPL FAQ for some more information.
+
+ Q 1.3: Can I use Ethereal commercially?
+
+ A: Yes, if, for example, you mean "I work for a commercial
+ organization; can I use Ethereal to capture and analyze network
+ traffic in our company's networks or in our customer's networks?"
+
+ If you mean "Can I use Ethereal as part of my commercial product?",
+ see the next entry in the FAQ.
- A: There are currently 355 supported protocols and media, listed
+ Q 1.4: Can I use Ethereal as part of my commercial product?
+
+ A: As noted, Ethereal is licended under the GNU General Public
+ License. The GPL imposes conditions on your use of GPL'ed code in your
+ own products; you cannot, for example, make a "derived work" from
+ Ethereal, by making modifications to it, and then sell the resulting
+ derived work and not allow recipients to give away the resulting work.
+ You must also make the changes you've made to the Ethereal source
+ available to all recipients of your modified version; those changes
+ must also be licensed under the terms of the GPL. See the GPL FAQ for
+ more details; in particular, note the answer to the question about
+ modifying a GPLed program and selling it commercially, and the
+ question about linking GPLed code with other code to make a
+ proprietary program.
+
+ You can combine a GPLed program such as Ethereal and a commercial
+ program as long as they communicate "at arm's length", as per this
+ item in the GPL FAQ.
+
+ Q 1.5: What protocols are currently supported?
+
+ A: There are currently 530 supported protocols and media, listed
below. Descriptions can be found in the ethereal(1) man page.
+ 3GPP2 A11
802.1q Virtual LAN
802.1x Authentication
+ AAL type 2 signalling protocol - Capability set 1 (Q.2630.1)
AFS (4.0) Replication Server call declarations
+ AIM Administrative
+ AIM Advertisements
+ AIM Buddylist Service
+ AIM Chat Navigation
+ AIM Chat Service
+ AIM Directory Search
+ AIM Generic Service
+ AIM ICQ
+ AIM Invitation Service
+ AIM Location
+ AIM Messaging
+ AIM OFT
+ AIM Popup
+ AIM Privacy Management Service
+ AIM Server Side Info
+ AIM Signon
+ AIM Statistics
+ AIM Translate
+ AIM User Lookup
+ ANSI A-I/F BSMAP
+ ANSI A-I/F DTAP
+ ANSI IS-637-A (SMS) Teleservice Layer
+ ANSI IS-637-A (SMS) Transport Layer
+ ANSI IS-683-A (OTA (Mobile))
+ ANSI IS-801 (Location Services (PLD))
+ ANSI Mobile Application Part
AOL Instant Messenger
ARCNET
ATM
ATM LAN Emulation
ATM OAM AAL
AVS WLAN Capture header
+ AX/4000 Test Block
Ad hoc On-demand Distance Vector Routing Protocol
- Ad hoc On-demand Distance Vector Routing Protocol v6
Address Resolution Protocol
Aggregate Server Access Protocol
+ Alert Standard Forum
+ Alteon - Transparent Proxy Cache Protocol
Andrew File System (AFS)
Apache JServ Protocol v1.3
+ Apple IP-over-IEEE 1394
AppleTalk Filing Protocol
AppleTalk Session Protocol
AppleTalk Transaction Protocol packet
Appletalk Address Resolution Protocol
+ Application Configuration Access Protocol
Async data over ISDN (V.120)
Authentication Header
BACnet Virtual Link Control
- Banyan Vines
+ BEA Tuxedo
+ BSS GPRS Protocol
+ BSSAP/BSAP
+ Banyan Vines ARP
+ Banyan Vines Echo
Banyan Vines Fragmentation Protocol
+ Banyan Vines ICP
+ Banyan Vines IP
+ Banyan Vines IPC
+ Banyan Vines LLC
+ Banyan Vines RTP
Banyan Vines SPP
+ Basic Encoding Rules (ASN.1 X.690)
+ Bearer Independent Call Control
+ Bi-directional Fault Detection Control Message
Blocks Extensible Exchange Protocol
+ Blubster/Piolet MANOLITO Protocol
Boardwalk
Boot Parameters
Bootstrap Protocol
Border Gateway Protocol
Building Automation and Control Network APDU
Building Automation and Control Network NPDU
+ CCSDS
CDS Clerk Server Calls
+ Cast Client Control Protocol
Check Point High Availability Protocol
Checkpoint FW-1
Cisco Auto-RP
CoSine IPNOS L2 debug output
Common Open Policy Service
Common Unix Printing System (CUPS) Browsing Protocol
- DCE DFS Calls
+ Compuserve GIF
+ Connectionless Lightweight Directory Access Protocol
+ Cross Point Frame Injector
+ Cryptographic Message Syntax
DCE Distributed Time Service Local Server
DCE Distributed Time Service Provider
DCE Name Service
DCE RPC
DCE Security ID Mapper
DCE/RPC BOS Server
+ DCE/RPC BUDB
+ DCE/RPC BUTC
DCE/RPC CDS Solicitation
DCE/RPC Conversation Manager
+ DCE/RPC Directory Acl Interface
DCE/RPC Endpoint Mapper
+ DCE/RPC Endpoint Mapper4
DCE/RPC FLDB
DCE/RPC FLDB UBIK TRANSFER
DCE/RPC FLDB UBIKVOTE
+ DCE/RPC ICL RPC
DCE/RPC Kerberos V
+ DCE/RPC NCS 1.5.1 Local Location Broker
+ DCE/RPC Operations between registry server replicas
+ DCE/RPC Prop Attr
DCE/RPC RS_ACCT
+ DCE/RPC RS_BIND
DCE/RPC RS_MISC
+ DCE/RPC RS_PROP_ACCT
DCE/RPC RS_UNIX
+ DCE/RPC Registry Password Management
+ DCE/RPC Registry Server Attributes Schema
+ DCE/RPC Registry server propagation interface - ACLs.
+ DCE/RPC Registry server propagation interface - PGO items
+ DCE/RPC Registry server propagation interface - properties and poli
+cies
DCE/RPC Remote Management
DCE/RPC Repserver Calls
DCE/RPC TokenServer Calls
DCOM OXID Resolver
DCOM Remote Activation
DEC Spanning Tree Protocol
+ DFS Calls
+ DHCP Failover
DHCPv6
+ DICOM
DNS Control Program Server
Data
Data Link SWitching
Datagram Delivery Protocol
Diameter Protocol
Distance Vector Multicast Routing Protocol
- Distributed Checksum Clearinghouse Prototocl
+ Distcc Distributed Compiler
+ Distributed Checksum Clearinghouse Protocol
+ Distributed Network Protocol 3.0
Domain Name Service
- Dummy Protocol
Dynamic DNS Tools Protocol
+ Echo
Encapsulating Security Payload
+ Endpoint Name Resolution Protocol
Enhanced Interior Gateway Routing Protocol
+ EtherNet/IP (Industrial Protocol)
Ethernet
+ Ethernet over IP
Extensible Authentication Protocol
FC Extended Link Svc
FC Fabric Configuration Server
Fibre Channel Name Server
Fibre Channel Protocol for SCSI
Fibre Channel SW_ILS
+ Fibre Channel Security Protocol
+ Fibre Channel Single Byte Command
File Transfer Protocol (FTP)
Financial Information eXchange Protocol
Frame
Frame Relay
GARP Multicast Registration Protocol
GARP VLAN Registration Protocol
+ GPRS Network service
GPRS Tunneling Protocol
- GPRS Tunnelling Protocol v0
- GPRS Tunnelling Protocol v1
+ GSM A-I/F BSSMAP
+ GSM A-I/F DTAP
+ GSM A-I/F RP
+ GSM Mobile Application Part
+ GSM SMS TPDU (GSM 03.40)
+ GSM Short Message Service User Data
General Inter-ORB Protocol
Generic Routing Encapsulation
Generic Security Service Application Program Interface
Gnutella Protocol
+ H225
+ H235-SECURITY-MESSAGES
+ H245
+ H4501
+ HP Extended Local-Link Control
+ HP Remote Maintenance Protocol
Hummingbird NFS Daemon
HyperSCSI
Hypertext Transfer Protocol
ICQ Protocol
+ IEEE 802.11 Radiotap Capture header
IEEE 802.11 wireless LAN
IEEE 802.11 wireless LAN management frame
ILMI
+ IP Device Control (SS7 over IP)
IP Over FC
IP Payload Compression
+ IP Virtual Services Sync Daemon
IPX Message
IPX Routing Information Protocol
+ IPX WAN
ISDN
ISDN Q.921-User Adaptation Layer
ISDN User Part
ISO 10589 ISIS InTRA Domain Routeing Information Exchange Protocol
ISO 8073 COTP Connection-Oriented Transport Protocol
+ ISO 8327-1 OSI Session Protocol
ISO 8473 CLNP ConnectionLess Network Protocol
ISO 8602 CLTP ConnectionLess Transport Protocol
+ ISO 8823 OSI Presentation Protocol
ISO 9542 ESIS Routeing Information Exchange Protocol
+ ITU-T E.164 number
ITU-T Recommendation H.261
+ ITU-T Recommendation H.263 RTP Payload header (RFC2190)
+ InMon sFlow
+ Intel ANS probe
+ Intelligent Platform Management Interface
Inter-Access-Point Protocol
+ Inter-Asterisk eXchange v2
+ InterSwitch Message Protocol
Interbase
Internet Cache Protocol
Internet Content Adaptation Protocol
Internet Control Message Protocol
Internet Control Message Protocol v6
Internet Group Management Protocol
+ Internet Group membership Authentication Protocol
Internet Message Access Protocol
Internet Printing Protocol
Internet Protocol
Internet Relay Chat
Internet Security Association and Key Management Protocol
Internetwork Packet eXchange
+ JPEG File Interchange Format
+ Jabber XML Messaging
Java RMI
Java Serialization
Kerberos
+ Kerberos Administration
Kernel Lock Manager
+ LWAP Control Message
+ LWAPP Encapsulated Packet
+ LWAPP Layer 3 Packet
Label Distribution Protocol
+ Laplink
Layer 2 Tunneling Protocol
Lightweight Directory Access 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)
Linux cooked-mode capture
Local Management Interface
LocalTalk Link Access Protocol
+ Logical Link Control GPRS
Logical-Link Control
Lucent/Ascend debug output
MDS Header
+ MIME Multipart Media Encapsulation
MMS Message Encapsulation
+ MS Kpasswd
MS Proxy Protocol
+ MSN Messenger Service
MSNIP: Multicast Source Notification of Interest Protocol
MTP 2 Transparent Proxy
MTP 2 User Adaptation Layer
MTP 3 User Adaptation Layer
MTP2 Peer Adaptation Layer
+ Media Type
+ Media Type: message/http
Message Transfer Part Level 2
Message Transfer Part Level 3
Message Transfer Part Level 3 Management
+ Microsoft Directory Replication Service
Microsoft Distributed File System
+ Microsoft Distributed Link Tracking Server Service
+ Microsoft Encrypted File System Service
+ Microsoft Eventlog Service
Microsoft Exchange MAPI
+ Microsoft File Replication Service
+ Microsoft File Replication Service API
Microsoft Local Security Architecture
Microsoft Local Security Architecture (Directory Services)
+ Microsoft Messenger Service
Microsoft Network Logon
Microsoft Registry
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
Microsoft Workstation Service
Mobile IP
+ Mobile IPv6
Modbus/TCP
Mount Service
MultiProtocol Label Switching Header
Multicast Router DISCovery protocol
Multicast Source Discovery Protocol
+ Multiprotocol Label Switching Echo
MySQL Protocol
NFSACL
NFSAUTH
NetBIOS Session Service
NetBIOS over IPX
NetWare Core Protocol
+ NetWare Link Services Protocol
+ NetWare Serialization Protocol
Network Data Management Protocol
Network File System
Network Lock Manager Protocol
Network Status Monitor CallBack Protocol
Network Status Monitor Protocol
Network Time Protocol
+ Nortel SONMP
Novell Distributed Print System
+ Novell Modular Authentication Service
Null/Loopback
+ OSI ISO 8571 FTAM Protocol
+ OSI ISO/IEC 10035-1 ACSE Protocol
Open Shortest Path First
+ OpenBSD Encapsulating device
OpenBSD Packet Filter log file
+ OpenBSD Packet Filter log file, pre 3.4
+ Optimized Link State Routing Protocol
PC NFS
+ PKCS#1
+ POSTGRESQL
PPP Bandwidth Allocation Control Protocol
PPP Bandwidth Allocation Protocol
PPP CDP Control Protocol
PPP MPLS Control Protocol
PPP Multilink Protocol
PPP Multiplexing
+ PPP OSI Control Protocol
PPP Password Authentication Protocol
PPP VJ Compression
PPP-over-Ethernet Discovery
PPP-over-Ethernet Session
PPPMux Control Protocol
+ Packed Encoding Rules (ASN.1 X.691)
+ PacketCable
Point-to-Point Protocol
Point-to-Point Tunnelling Protocol
Portmap
Post Office Protocol
Pragmatic General Multicast
+ Precision Time Protocol (IEEE1588)
Prism
Privilege Server operations
Protocol Independent Multicast
Q.2931
Q.931
+ Q.933
Quake II Network Protocol
Quake III Arena Network Protocol
Quake Network Protocol
QuakeWorld Network Protocol
Qualified Logical Link Control
RFC 2250 MPEG1
+ RFC 2833 RTP Event
RIPng
RPC Browser
+ RS Interface properties
RSTAT
+ RSYNC File Synchroniser
RX Protocol
Radio Access Network Application Part
Radius Protocol
Raw packet data
Real Time Streaming Protocol
+ Real-Time Publish-Subscribe Wire Protocol
Real-Time Transport Protocol
Real-time Transport Control Protocol
Registry Server Attributes Manipulation Interface
Registry server administration operations.
+ Remote Management Control Protocol
Remote Override interface
Remote Procedure Call
Remote Program Load
Remote Quota
Remote Shell
+ Remote Shutdown
Remote Wall protocol
Remote sec_login preauth interface.
Resource ReserVation Protocol (RSVP)
Routing Table Maintenance Protocol
SADMIND
SCSI
+ SEBEK - Kernel Data Capture
SGI Mount Service
SMB (Server Message Block Protocol)
SMB MailSlot Protocol
SPRAY
SS7 SCCP-User Adaptation Layer
SSCOP
+ SSH Protocol
Secure Socket Layer
Sequenced Packet eXchange
Service Advertisement Protocol
Session Announcement Protocol
Session Description Protocol
Session Initiation Protocol
+ Session Initiation Protocol (SIP as raw text)
Short Message Peer to Peer
+ Signaling Compression
Signalling Connection Control Part
Signalling Connection Control Part Management
Simple Mail Transfer Protocol
Simple Network Management Protocol
+ Simple Traversal of UDP Through NAT
Sinec H1 Protocol
+ Sipfrag
Skinny Client Control Protocol
SliMP3 Communication Protocol
Socks Protocol
+ SoulSeek Protocol
Spanning Tree Protocol
Spnego
Stream Control Transmission Protocol
+ Subnetwork Dependent Convergence Protocol
+ Symantec Enterprise Firewall
Synchronous Data Link Control (SDLC)
Syslog message
Systems Network Architecture
+ Systems Network Architecture XID
+ T38
TACACS
TACACS+
+ TEI Management Procedure, Channel D (LAPD)
+ TEREDO Tunneling IPv6 over UDP through NATs
TPKT
Tabular Data Stream
Tazmen Sniffer Protocol
Time Synchronization Protocol
Token-Ring
Token-Ring Media Access Control
+ Transaction Capabilities Application Part
Transmission Control Protocol
Transparent Network Substrate Protocol
Trivial File Transfer Protocol
+ UDP Encapsulation of IPsec Packets
Universal Computer Protocol
User Datagram Protocol
Virtual Router Redundancy Protocol
Virtual Trunking Protocol
+ WAP Binary XML
+ WAP Session Initiation Request
Web Cache Coordination Protocol
+ WebSphere MQ
+ WebSphere MQ Programmable Command Formats
+ Wellfleet Breath of Life
Wellfleet Compression
Wellfleet HDLC
Who
X.25
X.25 over TCP
X.29
+ X.509 Authentication Framework
+ X.509 Certificate Extensions
+ X.509 Information Framework
+ X.509 Selected Attribute Types
X11
Xyplex
Yahoo Messenger Protocol
+ Yahoo YMSG Messenger Protocol
Yellow Pages Bind
Yellow Pages Passwd
Yellow Pages Service
Yellow Pages Transfer
Zebra Protocol
Zone Information Protocol
+ eDonkey Protocol
+ giFT Internet File Transfer
iSCSI
+ iSNS
- Q 1.3: Are there any plans to support {your favorite protocol}?
+ Q 1.6: Are there any plans to support {your favorite protocol}?
A: Support for particular protocols is added to Ethereal as a result
of people contributing that support; no formal plans for adding
support for particular protocols in particular future releases exist.
- Q 1.4: Can Ethereal read capture files from {your favorite network
+ Q 1.7: Can Ethereal read capture files from {your favorite network
analyzer}?
A: Support for particular protocols is added to Ethereal as a result
Note that there is no guarantee that we will be able to
reverse-engineer a capture file format.
- Q 1.5: What devices can Ethereal use to capture packets?
+ Q 1.8: What devices can Ethereal use to capture packets?
A: Ethereal can read live data from Ethernet, Token-Ring, FDDI, serial
(PPP and SLIP) (if the OS on which it's running allows Ethereal to do
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).
+ _EWEB_MAILTO).
It can also read a variety of capture file formats, including:
* libpcap/tcpdump
other applications or equipment, even if it cannot itself capture on
those network types.
- Q 1.6: How do you pronounce Ethereal? Where did the name come from?
+ Q 1.9: How do you pronounce Ethereal? Where did the name come from?
A: The English pronunciation can be found in Merriam-Webster's online
dictionary at
According to the book "Computer Networks" by Andrew Tannenbaum,
Ethernet was named after the "luminiferous ether" which was once
thought to carry electromagnetic radiation. Taking that into
- consideration, Ethereal seemed like an appropriate name for an
- Ethernet sniffer.
+ consideration, Ethereal seemed like an appropriate name for something
+ that started out as an Ethernet analyzer.
+
+Downloading Ethereal
- DOWNLOADING ETHEREAL
Q 2.1: I downloaded the Win32 installer, but when I try to run it, I
get an error.
the server. You should try again later, or try the local mirror or the
Wiretapped.net mirror.
- INSTALLING ETHEREAL
+Installing Ethereal
+
Q 3.1: I installed an Ethereal RPM, but Ethereal doesn't seem to be
installed; only Tethereal is installed.
- A: Red Hat RPMs for Ethereal put only the non-GUI components into the
- ethereal RPM, the fact that Ethereal is a GUI program nonwithstanding;
- there's a separate ethereal-gnome RPM that includes GUI components
- such as Ethereal itself, the fact that Ethereal doesn't use GNOME
- nonwithstanding. Find the ethereal-gnome RPM, and install that also.
+ 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 nonwithstanding; newer versions make it a bit clearer by
+ giving that RPM a name starting with ethereal-base.
+
+ In those older versions, there's a separate ethereal-gnome RPM that
+ includes GUI components such as Ethereal itself, the fact that
+ Ethereal doesn't use GNOME nonwithstanding; newer versions make it a
+ bit clearer by giving that RPM a name starting with ethereal-gtk+.
+
+ Find the ethereal-gnome or ethereal-gtk+ RPM, and install that also.
+
+Building Ethereal
- BUILDING ETHEREAL
Q 4.1: The configure script can't find pcap.h or bpf.h, but I have
libpcap installed.
strange location. If this is the case, you may have to tweak
aclocal.m4.
- Q 4.2: Why do I get the error
+ Q 4.2: Why do I get the error
dftest_DEPENDENCIES was already defined in condition TRUE, which
implies condition HAVE_PLUGINS_TRUE
- when I try to build Ethereal from CVS or a CVS snapshot?
+ when I try to build Ethereal from SVN or a SVN snapshot?
A: You probably have automake 1.5 installed on your machine (the
command automake --version will report the version of automake on your
machine). 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 failed because of an undefined reference to
- snmp_set_full_objid.
-
- A: You probably have the shared library for UCD SNMP 4.1.1 installed
- (so that snmp_set_full_objid is a macro, rather than a routine in the
- SNMP shared library), but the `development' package for an earlier or
- later UCD SNMP library (so that snmp_set_full_objid is not defined as
- a macro, causing Ethereal to attempt to call it as a routine).
-
- If you are on a Linux system that uses RPMs, and the UCD SNMP packages
- are installed as RPMs, the command rpm -qa | grep snmp will report the
- versions of the SNMP packages you have installed; they should all have
- the same version number, such as 4.0.1 or 4.1.1 or 4.1.2. If they
- don't, remove the RPM for the development package (which will probably
- have a name beginning with ucd-snmp-devel) and install the version of
- the development package with the same version number as the other
- ucd-snmp packages have.
-
- After installing the 4.1.1 version of the UCD SNMP header files, do a
- make clean and then rebuild Ethereal.
-
- Q 4.4: The link fails with a number of "Output line too long."
- messages followed by linker errors.
+ Q 4.3: The link fails with a number of "Output line too long."
+ messages followed by linker errors.
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
searching the directory with the version of sed that came with the OS
should make the problem go away.
- Q 4.5: The link fails on Solaris because plugin_list is undefined.
+ Q 4.4: The link fails on Solaris because 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,
persists, un-install them and try installing one of the other versions
mentioned.)
- Q 4.6: The build fails on Windows because of conflicts between
- winsock.h and winsock2.h.
+ Q 4.5: The build fails on Windows 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
Note that the installed version of the developer's pack should be the
same version as the version of WinPcap you have installed.
- USING ETHEREAL
+Using Ethereal
+
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.
may exist for other "auto-sensing" or "dual-speed" hubs.
Some switches have the ability to replicate all traffic on all ports
- to a single port so that you can plug your sniffer into that single
+ to a single port so that you can plug your analyzer into that single
port to sniff all traffic. You would have to check the documentation
for the switch to see if this is possible and, if so, to see how to do
- this. See, for example:
- * this documentation from Cisco on the Switched Port Analyzer (SPAN)
- feature on Catalyst switches;
- * documentation from HP on how to set `monitoring'/`mirroring' on
- ports on the console for HP Advancestack Switch 208 and 224;
- * the `Network Monitoring Port Features' section of chapter 6 of
- documentation from HP for HP ProCurve Switches 1600M, 2424M,
- 4000M, and 8000M.
+ this. See the switch reference page on the Ethereal Wiki for
+ information on some switches. (Note that it's a Wiki, so you can
+ update or fix that information, or add additional information on those
+ switches or information on new switches, yourself.)
Note also that many firewall/NAT boxes have a switch built into them;
this includes many of the "cable/DSL router" boxes. If you have a box
In the case of token ring interfaces, the drivers for some of them, on
Windows, may require you to enable promiscuous mode in order to
capture in promiscuous mode. Ask the vendor of the card how to do
- this.
+ this, or see, for example, this information on promiscuous mode on
+ some Madge token ring adapters (note that those cards can have
+ promiscuous mode disabled permanently, in which case you can't enable
+ it).
In the case of wireless LAN interfaces, it appears that, when those
interfaces are promiscuously sniffing, they're running in a
promiscuous mode.
Q 5.2: I can't see any TCP packets other than packets to and from my
- machine, even though another sniffer on the network sees those
+ machine, even though another analyzer on the network sees those
packets.
A: You're probably not seeing any packets other than unicast packets
traffic, it's a problem with unicast traffic, as you also won't see
all UDP traffic between other machines.
- I.e., this is probably the same problem discussed in the previous
- question; see the response to that question.
+ 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.
+
+ 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 other machines on the switch. ARP packets are often
+ broadcast packets, which are sent to all switch ports.
+
+ 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?
+
+ A: If you are running Ethereal on Windows NT 4.0, Windows 2000,
+ Windows XP, or Windows Server, 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.
+
+ If you are running on Windows 95/98/Me, or if you are running on
+ Windows NT 4.0/2000/XP/Server and have administrator privileges or a
+ WinPcap-based program has been run with those privileges since the
+ machine rebooted, 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.
+
+ 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 5.3: I can set a display filter just fine, but capture filters don't
- work.
+ 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 3.0 doesn't support PPP WAN interfaces, and WinPcap 2.3
+ doesn't support PPP WAN interfaces on Windows NT/2000/XP/Server,
+ so Ethereal cannot capture packets on those devices with WinPcap
+ 3.0, or with WInPcap 2.x when running on Windows
+ NT/2000/XP/Server. Regular dial-up lines, ISDN lines, and various
+ other lines such as T1/E1 lines are all PPP interfaces. This may
+ cause the interface not to show up on the list of interfaces in
+ the "Capture Options" dialog.
+ 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.polito.it 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: All of those devices support Internet access using the
+ Point-to-Point (PPP) protocol; WinPcap 3.0 doesn't support PPP
+ interfaces, and WinPcap 2.x doesn't support PPP interfaces on Windows
+ NT/2000/XP/Server, so Ethereal cannot capture packets on those devices
+ with WinPcap 3.0, or with WinPcap 2.x when running on Windows
+ NT/2000/XP/Server. This may cause the interface not to show up on the
+ list of interfaces in the "Capture Options" dialog.
+
+ 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. 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.
+
+ 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.
+
+ Therefore, if the OS or the libpcap library don't support capturing on
+ a particular network interface device, Ethereal won't be able to
+ capture on that device.
+
+ On Linux, note that you need to have "packet socket" support enabled
+ in your kernel; see the "Packet socket" item in the Linux
+ "Configure.help" file.
+
+ On BSD, note that you need to have BPF support enabled in your kernel;
+ see the documentation for your system for information on how to enable
+ BPF support (if it's not enabled by default on your system).
+
+ On DEC OSF/1, Digital UNIX, or Tru64 UNIX, note that you need to have
+ packet filtering support in your kernel; the doconfig command will
+ allow you to configure and build a new kernel with that option.
+
+ 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.
+
+ 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, and its driver and libraries, installed can capture traffic
+ with those cards with libpcap-based applications. You would either
+ have to have a version of Ethereal built with that version of libpcap,
+ or a dynamically-linked version 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.)
+
+ Q 5.10: How do I put an interface into promiscuous mode?
+
+ A: By not disabling promiscuous mode when running Ethereal or
+ Tethereal.
+
+ Note, however, that:
+ * the form of promiscuous mode that libpcap (the library that
+ programs such as tcpdump, Ethereal, etc. use to do packet capture)
+ turns on will not necessarily be shown if you run ifconfig on the
+ interface on a UNIX system;
+ * some network interfaces might not support promiscuous mode, and
+ some drivers might not allow promiscuous mode to be turned on -
+ see this earlier question for more information on that;
+ * the fact that you're not seeing any traffic, or are only seeing
+ broadcast traffic, or aren't seeing any non-broadcast traffic
+ other than traffic to or from the machine running Ethereal, does
+ not mean that promiscuous mode isn't on - see this earlier
+ question for more information on that.
+
+ 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.
A: Capture filters currently use a different syntax than display
filters. Here's the corresponding section from the ethereal(1) man
The capture filter syntax used by libpcap can be found in the
tcpdump(8) man page.
- Q 5.4: I'm entering valid capture filters, but I still get "parse
+ Q 5.12: I'm entering valid capture filters, but I still get "parse
error" errors.
A: There is a bug in some versions of libpcap/WinPcap that cause it to
WinPcap, you will need to un-install WinPcap and then download and
install WinPcap 2.3.
- Q 5.5: I saved a filter and tried to use its name to filter the
+ 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
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 5.6: Why am I seeing lots of packets with incorrect TCP checksums?
+ Q 5.14: Why am I seeing lots of packets with incorrect TCP checksums?
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
tcp.check_checksum:false command-line flag, or manually set in your
preferences file by adding a tcp.check_checksum:false line.
- Q 5.7: I've just installed Ethereal, and the traffic on my local LAN
+ Q 5.15: I've just installed Ethereal, and the traffic on my local LAN
is boring.
A: We have a collection of strange and exotic sample capture files at
http://www.ethereal.com/sample/
- Q 5.8: When I run Ethereal on Solaris 8, it dies with a Bus Error when
- I start it.
+ Q 5.16: When I run Ethereal on Solaris 8, it dies with a Bus Error
+ when I start it.
A: Some versions of the GTK+ library from www.sunfreeware.org appear
to be buggy, causing Ethereal to drop core with a Bus Error.
Similar problems may exist with older versions of GTK+ for earlier
versions of Solaris.
- Q 5.9: I'm running Ethereal on Linux; why do my time stamps have only
+ Q 5.17: When I run Ethereal, 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 5.18: When I run Tethereal with the "-x" option, it crashes 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.
+
+ To get a fixed version, either build the current SVN version from
+ anonymous SVN or a nightly SVN snapshot, or apply to tethereal.c in
+ the 0.10.0a source tarball the changes between the broken and the
+ fixed versions, which you can download with the URL
+ http://www.ethereal.com/cgi-bin/viewcvs.cgi/ethereal/tethereal.c.diff?
+ r2=1.211&r1=1.210&diff_format=u and (re-)build from source. It might
+ be easier to get the SVN version than to get the patch and apply it to
+ the 0.10.0a source tarball, but it's probably easier to build from the
+ source tarball than from the SVN version, as you'll need to have more
+ tools and make more steps to generate from the SVN version some files
+ that are bundled with the source tarball.
+
+ Note that to build from the 0.10.0a source tarball on Windows with
+ Microsoft Visual C++, you will need to get a file that was missing
+ from the 0.10.0a source tarball; see the FAQ for that problem.
+
+ 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.
+
+ 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 5.20: When I try to run Ethereal, it complains 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 5.21: I'm running Ethereal on Linux; why do my time stamps have only
100ms resolution, rather than 1us resolution?
A: Ethereal gets time stamps from libpcap/WinPcap, and libpcap/WinPcap
have to run a standard kernel from kernel.org in order to get
high-resolution time stamps.
- Q 5.10: I'm capturing packets on {Windows 95, Windows 98, Windows Me};
- why are the time stamps on packets wrong?
+ Q 5.22: I'm capturing packets on {Windows 95, Windows 98, Windows Me};
+ why are the time stamps on packets wrong?
- A: This is due to a bug in WinPcap. The bug should be fixed in the
- WinPcap 3.0 alpha release - note that it's an alpha release, so it may
- be buggier than the current production release of WinPcap; please
- report those bugs to the WinPcap developers, and help them try to
- track down the problem, so that they can fix it for the final release.
+ A: This is due to a bug in WinPcap. The bug should be fixed in WinPcap
+ 3.0.
- Q 5.11: When I try to run Ethereal on Windows, it fails to run because
+ Q 5.23: When I try to run Ethereal on Windows, it fails to run because
it can't find packet.dll.
A: In older versions of Ethereal, there were two binary distributions
Web site, the local mirror of the WinPcap Web site, or the
Wiretapped.net mirror of the WinPcap site.
- Q 5.12: 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: If you are running Ethereal on a UNIX-flavored platform, you may
- need to run Ethereal from an account with sufficient privileges to
- capture packets, such as the super-user account. 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.
-
- If you are running Ethereal on Windows NT 4.0, Windows 2000, Windows
- XP, or Windows Server, 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.
-
- If you are running on a UNIX-flavored platform and have sufficient
- privileges, or if you are running on Windows 95/98/Me, or if you are
- running on Windows NT 4.0/2000/XP/Server and have administrator
- privileges or a WinPcap program has been run with those privileges
- since the machine rebooted, 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 Windows, it also relies on
- the device driver that comes with WinPcap (which is a version of
- libpcap for Windows).
-
- Therefore, if the OS, the libpcap 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.
-
- On Linux, note that you need to have "packet socket" support enabled
- in your kernel; see the "Packet socket" item in the Linux
- "Configure.help" file.
-
- On BSD, note that you need to have BPF support enabled in your kernel;
- see the documentation for your system for information on how to enable
- BPF support (if it's not enabled by default on your system).
-
- On DEC OSF/1, Digital UNIX, or Tru64 UNIX, note that you need to have
- packet filtering support in your kernel; the doconfig command will
- allow you to configure and build a new kernel with that option.
-
- On Windows, note that:
- * 2.02 and earlier versions of the WinPcap driver and library that
- Ethereal uses for packet capture didn't support Token Ring
- interfaces; the current version, 2.3, does 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.
- * 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 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.
- * WinPcap doesn't support PPP WAN interfaces on Windows
- NT/2000/XP/Server, so Ethereal cannot capture packets on those
- devices when running on Windows NT/2000/XP/Server. Regular dial-up
- lines, ISDN lines, and various other lines such as T1/E1 lines are
- all PPP interfaces. This may cause the interface not to show up on
- the list of interfaces in the "Capture Options" dialog.
- * WinPcap currently 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
- versions refuse to operate if they detect that they're running on
- a multiprocessor machine, which means that they may not show any
- network interfaces.
-
- 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 - or, on Windows, the
- tcpdump port to Windows, named WinDump; see the WinDump Web site, the
- local mirror of the WinDump Web site, or the Wiretapped.net mirror of
- the WinDump site, for information on using WinDump.
-
- If you can capture on the interface with tcpdump/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 (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/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 libpcap/WinPcap library and, if this is Windows, the WinPcap
- device driver;
-
- so:
- * if you are using Windows, 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 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).
-
- You may also want to ask the ethereal-users@ethereal.com and, if this
- is a UNIX-flavored platform, 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/WinDump, not just with Ethereal.
-
- Q 5.13: I'm running Ethereal on Windows NT/2000/XP/Server; my machine
+ Q 5.24: I'm running Ethereal on Windows NT/2000/XP/Server; 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
Preferences" dialog box, but this may mean that outgoing packets, or
incoming packets, won't be seen in the capture.
- Q 5.14: I'm running Ethereal on Windows 95/98/Me, on a machine with
+ 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.
capture only on the first such interface; Ethereal is a
libpcap/WinPcap-based application.
- Q 5.15: I have an XXX network card on my machine; if I try to capture
- on it, my machine crashes or resets itself.
+ Q 5.26: I'm running Ethereal on Windows, and I'm 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 software installed on their machine. If that's the
+ cause of the problem, you will have to remove the VPN software in
+ order to have Ethereal (or any other application using WinPcap) see
+ outgoing packets; unfortunately, neither we nor the WinPcap developers
+ know any way to make WinPcap and the VPN software work well together.
+
+ Also, some drivers for Windows (especially some wireless network
+ interface drivers) apparently do not, when running in promiscuous
+ mode, arrange that 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.
+
+ 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 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.
+
+ Otherwise, on Windows, see the response to this question and, on a
+ UNIX-flavored OS, see the response to this question.
+
+ 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.
A: This is almost certainly a problem with one or more of:
* the operating system you're using;
Linux distribution, report the problem to whoever produces the
distribution).
- Q 5.16: My machine crashes or resets itself when I select "Start" from
- the "Capture" menu or select "Preferences" from the "Edit" menu.
+ Q 5.29: My machine crashes or resets itself when I select "Start" from
+ the "Capture" menu or select "Preferences" from the "Edit" menu.
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
or, for Windows, WinPcap bug that causes the system to crash when this
happens; see the previous question.
- Q 5.17: Does Ethereal work on Windows ME?
+ Q 5.30: 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
+ didn't support Windows Me. You should also install the latest version
of Ethereal as well.
- Q 5.18: Does Ethereal work on Windows XP?
+ Q 5.31: 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.
- Q 5.19: Why doesn't Ethereal correctly identify RTP packets? It shows
+ Q 5.32: Why doesn't Ethereal correctly identify RTP packets? It shows
them only as UDP.
A: Ethereal can identify a UDP datagram as containing a packet of a
both the source and destination ports of the packet should be
dissected as some particular protocol.
- Q 5.20: Why doesn't Ethereal show Yahoo Messenger packets in captures
+ Q 5.33: Why doesn't Ethereal show Yahoo Messenger packets in captures
that contain Yahoo Messenger traffic?
A: Ethereal only recognizes as Yahoo Messenger traffic packets to or
- from TCP port 3050 that begin with "YPNS" or "YHOO". This means that
- 1. 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);
- 2. Yahoo Messenger packets that begin with "YMSG", as packets for
- some versions of the protocol apparently do, will not be
- recognized as Yahoo Messenger packets.
+ 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).
- Q 5.21: Why do I get the error
+ Q 5.34: Why do I get the error
Gdk-ERROR **: Palettized display (256-colour) mode not supported on
Windows.
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; that toolkit doesn't
- support 256-color mode on Windows - it requires HiColor (16-bit
- colors) or more. If your display supports more than 256 colors, switch
- to a display mode with more colors; if it doesn't support more than
- 256 colors, you will be unable to run Ethereal.
+ 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 5.22: When I capture on Windows in promiscuous mode, I can see
+ 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?
+ in their entirety?
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.
- Q 5.23: How can I capture raw 802.11 packets, including non-data
- (management, beacon) packets?
-
- A: The answer to this depends on the operating system on which you're
- running and the 802.11 interface you're using.
+ Q 5.36: I'm capturing packets on a machine on a VLAN; why don't the
+ packets I'm capturing have VLAN tags?
+
+ 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 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.
+
+ Q 5.37: How can I capture raw 802.11 packets, including non-data
+ (management, beacon) packets?
+
+ A: That depends on the operating system on which you're running, and
+ on the 802.11 interface on which you're capturing.
+
+ This would probably require that you capture in promiscuous mode or in
+ the mode called "monitor mode" or "RFMON mode". On some platforms, or
+ with some cards, this might require that you capture in monitor mode -
+ promiscuous mode might not be sufficient. If you want to capture
+ traffic on networks other than the one with which you're associated,
+ you will have to capture in monitor mode.
+
+ Not all operating systems support capturing non-data packets and, even
+ on operating systems that do support it, not all drivers, and thus not
+ all interfaces, support it. Even on those that do, monitor mode might
+ not be supported by the operating system or by the drivers for all
+ interfaces.
+
+ NOTE: an interface running in monitor mode will, on most if not all
+ platforms, not be able to act as a regular network interface; putting
+ it into monitor mode will, in effect, take your machine off of
+ whatever network it's on as long as the interface is in monitor mode,
+ allowing it only to passively capture packets.
+
+ This means that you should disable name resolution when capturing in
+ monitor mode; otherwise, when Ethereal (or Tethereal, or tcpdump)
+ tries to display IP addresses as host names, it will probably block
+ for a long time trying to resolve the name because it will not be able
+ to communicate with any DNS or NIS servers.
+
+ There are FAQ items below with information on capturing in monitor
+ mode on Linux, FreeBSD, and NetBSD.
+
+ On Windows, you will not be able to capture in monitor mode on any
+ interfaces, and you might not be able to capture in promiscuous mode,
+ either. You might have some success in promiscuous mode with Centrino
+ interfaces, although you will need Ethereal 0.10.6 or later in order
+ to have the non-data packets recognized and properly dissected.
+
+ You will not be able to capture in monitor mode on any other platforms
+ (including Mac OS X). You might be able to capture in promiscuous
+ mode, but this won't capture non-data packets.
+
+ Q 5.38: How do I capture on an 802.11 device in monitor mode on Linux?
+
+ A: Whether you will be able to capture in monitor mode depends on the
+ card and driver you're using. See this page of Linux 802.11b
+ information for details on 802.11b wireless cards, including
+ information on the chips they use, and see this page of Linux
+ 802.11b+/a/g information for details on 802.11b+, 802.11a, and 802.11g
+ wireless cards, including information on the chips they use.
Cisco Aironet cards:
- The only platforms that allow Ethereal to capture raw 802.11 packets
- on Cisco Aironet cards are:
- * Linux, with a 2.4.6 or later kernel;
- * FreeBSD 4.6 or later, as the driver in FreeBSD 4.5 has bugs that
- cause packets not to be captured correctly, and the driver in
- releases prior to 4.5 didn't support capturing raw packets.
-
- On FreeBSD, the ancontrol utility must be used; do not enable the full
- Aironet header via BPF, as Ethereal doesn't currently support that.
-
- On Linux, you will need to do
-
-echo "Mode: rfmon" >/proc/driver/aironet/ethN/Config
-
- if your Aironet card is ethN. To capture traffic from any BSS, do
-
-echo "Mode: y" >/proc/driver/aironet/ethN/Config
-
- and to return to the normal mode, do
-
-echo "Mode: ess" >/proc/driver/aironet/ethN/Config
-
- In either case, Ethereal would have to be linked with libpcap 0.7.1 or
- later; this means that most Ethereal binary packages won't work unless
- they're statically linked with libpcap 0.7.1 or later, or they're
- dynamically linked with libpcap and your system has a libpcap 0.7.1 or
- later shared library installed (note that libpcap source package from
- tcpdump.org does not build shared libraries).
-
- Cards using the Prism II chip set (see this page of Linux 802.11
- information for details on wireless cards, including information on
- the chips they use):
+ On Linux with the driver in the 2.4.6 through 2.4.19 kernel:
+ 1. Put the card into monitor mode with the command echo "Mode: rfmon"
+ >/proc/driver/aironet/interface/Config. If you want to capture
+ traffic for any BSS rather than just the BSS with which the card
+ is associated, use "Mode: y" rather than "Mode: rfmon".
+ 2. When the capture completes, turn off monitor mode with the command
+ echo "Mode: ess" >/proc/driver/aironet/interface/Config.
+
+ On Linux with the driver in the 2.4.20 or later kernel, or with the
+ CVS drivers from the airo-linux SourceForge site, you will have to
+ capture on the wifiN interface if your Aironet card is ethN, after
+ running the commands listed above.
+
+ In all of those cases, Ethereal would have to be linked with libpcap
+ 0.7.1 or later; this means that most Ethereal binary packages won't
+ work unless they're statically linked with libpcap 0.7.1 or later, or
+ they're dynamically linked with libpcap and your system has a libpcap
+ 0.7.1 or later shared library installed (note that libpcap source
+ package from tcpdump.org does not build shared libraries). Some binary
+ packaging mechanisms might make it difficult to install Ethereal
+ binary packages built to depend on older libpcap binary packages if
+ you have a newer libpcap binary package installed; the installer
+ programs for those packaging mechanisms might support disabling
+ dependency checking so that they will install Ethereal even though a
+ newer version of libpcap is installed.
+
+ Cards using the Prism II chip set:
You can capture raw 802.11 packets with Prism II cards on Linux
- systems with the 0.1.14-pre1 or later version of the linux-wlan-ng
+ systems with the 0.1.14-pre6 or later version of the linux-wlan-ng
drivers (see the linux-wlan page, and the linux-wlan-ng tarball
- directory), or with Solomon Peachy's patches to the linux-wlan-ng
- 0.1.13 drivers (see the `0132-packet-v71.diff' link on his software
- page; the patch speaks of 0.1.13-pre2, but appears to apply to 0.1.13
- as well). If you are using the 0.1.13 drivers, you might also want his
- `0132-promisc-v23.diff' patch as well; if you are using the
- 0.1.14-pre1 drivers, you might also want his
- `014p1-promiscfixes-v1.diff' patches - both of those are already in
- 0.1.14-pre2.
-
- Those require either Solomon's patch to libpcap 0.7.1 (see his
- `libpcap-0.7.1-prism.diff' file, or his RPMs of that version of
- libpcap), or the current CVS version of libpcap, which includes his
- patch (download it from the `Current Tar files' section of the
- tcpdump.org Web site).
-
- You may have to run a command to put the interface into monitor mode,
- or to change other interface settings.
- Earlier versions of the linux-wlan-ng drivers don't allow Ethereal to
- directly capture raw 802.11 packets on Prism II cards; however, on
- Linux systems with the linux-wlan-ng drivers version 0.1.6, the
- Prismdump utility can be used to capture packets; it saves packets in
- a form that Ethereal can read. Prismdump can be downloaded from this
- page on the developer.axis.com Web site.
+ directory), or with the hostap driver for Prism II/2.5/3.
- On other platforms, capturing raw 802.11 packets on Prism II cards is
- not currently supported.
+ Those require either Solomon Peachy's patch to libpcap 0.7.1 (see his
+ libpcap-0.7.1-prism.diff file, or his RPMs of that version of
+ libpcap), or the current CVS version of libpcap, which includes his
+ patch (download it from the "Current Tar files" section of the
+ tcpdump.org Web site). If you apply his patches to libpcap 0.7.1 and
+ rebuild and install libpcap, or if you build and install the current
+ CVS version of libpcap, you would have to rebuild Ethereal from
+ source, linking it with that new version of libpcap; an Ethereal
+ binary package would not work. Ethereal binary packages might work if
+ you install the libpcap-0.7.1-1prism.i386.rpm RPM, as it might install
+ a libpcap shared library in place of the one on your system.
+
+ With the linux-wlan-ng driver, you should:
+ 1. Put the card into monitor mode with the command wlanctl-ng
+ interface lnxreq_wlansniffer enable=true. You should request
+ 802.11 headers by adding to that command the option
+ prismheader=true or, if supported, wlanheader=true; the latter
+ might require libpcap 0.8.1 or later. You can also set the channel
+ to monitor by adding the argument channel=channel_number to that
+ command.
+ 2. When the capture completes, turn off monitor mode with the command
+ wlanctl-ng interface enable=false. You might also have to turn
+ 802.11 headers off with prismheader=false or wlanheader=false.
+
+ See the wlan-ng FAQ for additional information, although note that it
+ does not appear to be up-to-date.
+
+ With the hostap driver, you should:
+ 1. Put the card into monitor mode with the command iwpriv interface
+ monitor mode, where mode is 2 or 3 (mode 3 would require libpcap
+ 0.8.1 or later).
+ 2. When the capture completes, turn off monitor mode with the command
+ iwpriv interface monitor 0.
Orinoco Silver and Gold cards:
- On Linux systems, when using either the orinoco_cs-0.09b driver or the
- driver in at least some versions of the Linux kernel, the
- `orinoco-09b-packet-1.diff' patch on the Orinoco Monitor Mode Patch
- Page should allow you to do capture raw 802.11 packets.
+ On Linux systems, the current version of the SourceForge orinoco_cs
+ driver should support monitor mode. There also exist patches to
+ earlier versions of the Orinoco driver, on the Orinoco Monitor Mode
+ Patch Page, to add support for monitor mode. You will have to
+ determine which version of the driver you have, and select the
+ appropriate patch, if one is necessary.
- The patch appears to apply to the driver in the 2.4.18 kernel, but we
- don't know whether it works; the directions on that page are for the
- pcmcia-cs drivers, not for the driver in the kernel itself.
Note that the page indicates that not all versions of the Orinoco
- firmware support this patch. The Orinoco patches require Solomon
- Peachy's libpcap patches.
-
- On other platforms, capturing raw 802.11 packets on Orinoco cards is
- not currently supported.
-
- Other 802.11 interfaces:
-
- With other 802.11 interfaces, no platform allows Ethereal to capture
- raw 802.11 packets, as far as we know. If you know of other 802.11
- interfaces that are supported (note that there are many `Prism II
- cards', so your card might be a Prism II card), please let us know,
- and include URLs for sites containing any necessary patches to add
- this support.
-
- On platforms that don't allow Ethereal to capture raw 802.11 packets,
- the 802.11 network will appear like an Ethernet to Ethereal.
-
- Q 5.24: How can I capture packets with CRC errors?
+ firmware support this patch. It says, for some versions of the patch,
+ "This patch should allow monitor mode with v8.10 firmware (untested w/
+ 8.42);" if you have version 8.10 or later firmware on your Orinoco
+ cards, you might have to use those patches, with the corresponding
+ versions of the Orinoco driver, in order to run in monitor mode.
+
+ That patch is written for the drivers included with the pcmcia-cs
+ drivers, but works equally well for the Orinoco drivers provided with
+ Linux kernels up to 2.4.20. To apply a patch to your kernel drivers,
+ simply copy the orinoco-09b-patch.diff file to the
+ /usr/src/linux/drivers/net directory and patch according to the
+ directions on the Orinoco Monitor Mode Patch Page. You can double-
+ check the version of the Orinoco drivers that shipped with your kernel
+ by examining the first few lines of the orinoco.c file.
+
+ The Orinoco patches and SourceForge driver require either Solomon
+ Peachy's patch to libpcap 0.7.1 (see his libpcap-0.7.1-prism.diff
+ file, or his RPMs of that version of libpcap), or the current CVS
+ version of libpcap, which includes his patch (download it from the
+ "Current Tar files" section of the tcpdump.org Web site). If you apply
+ his patches to libpcap 0.7.1 and rebuild and install libpcap, or if
+ you build and install the current CVS version of libpcap, you would
+ have to rebuild Ethereal from source, linking it with that new version
+ of libpcap; an Ethereal binary package would not work. Ethereal binary
+ packages might work if you install the libpcap-0.7.1-1prism.i386.rpm
+ RPM, as it might install a libpcap shared library in place of the one
+ on your system.
+
+ With a driver that supports monitor mode, you should:
+ 1. Put the card into monitor mode with the command iwpriv interface
+ monitor mode channel_number, where mode is 1 or 2, and
+ channel_number is the number of the channel to monitor.
+ 2. When the capture completes, turn off monitor mode with the command
+ iwpriv interface monitor 0.
+
+ Cards with the Texas Instruments ACX100 chipset:
+
+ You can capture raw 802.11 packets with ACX100 cards on Linux systems
+ with the ACX100 OSS drivers available from the ACX100 wireless network
+ driver project SourceForge site.
+
+ With that driver:
+
+ 1. Put the card into monitor mode with the command iwpriv interface
+ monitor 2 channel_number, where channel_number is the number of
+ the channel to monitor.
+ 2. When the capture completes, turn off monitor mode with the command
+ iwpriv interface monitor 0.
+
+ Cards with Atheros Communications chipsets:
+
+ You can capture raw 802.11 packets with AR5K cards on Linux systems
+ with the v5_ar5k or madwifi drivers. For the v5ar5k driver you will
+ need the Linux wireless-tools version 25 or higher to put the card
+ into monitor mode. If you're using the madwifi driver, you can put the
+ card into monitor mode using iwconfig interface mode monitor, followed
+ by iwconfig interface channel channel to select a channel (if needed).
+
+ Other cards:
+
+ It might be possible to capture in monitor mode on other cards. If so,
+ please supply us with information on how to do so, so that we can
+ incorporate that information into this FAQ in the future.
+
+ Q 5.39: How do I capture on an 802.11 device in monitor mode on
+ FreeBSD?
+
+ A: On FreeBSD 5.2 and later, you should be able to capture in monitor
+ mode on 802.11 interfaces supported by the wi and acx drivers, if
+ Ethereal is linked with libpcap 0.8.1 or later, and on 802.11
+ interfaces supported by the an driver, if Ethereal is linked with
+ libpcap 0.7.1 or later.
+
+ For cards supported by the wi and acx drivers, you should:
+ 1. Put the card into monitor mode with the command ifconfig interface
+ monitor. You can also set the channel to monitor by adding the
+ argument channel channel_number to that command.
+ 2. When you start the capture, in Ethereal select "802.11" as the
+ "Link-layer header type", and in Tethereal add the command-line
+ argument -y 802.11.
+ 3. When the capture completes, turn off monitor mode with the command
+ ifconfig interface -monitor.
+
+ For cards supported by the an driver, you should:
+ 1. Put the card into monitor mode with the command ancontrol -i
+ interface -M flag, where flag should be the sum of:
+ + 1, to turn monitor mode on;
+ + 2, if you want to capture traffic from any BSS rather than
+ just the BSS with which the card is associated;
+ + 4, if you want to see beacon packets (capturing beacon
+ packets increases the CPU requirements of capturing).
+ 2. When the capture completes, turn off monitor mode with the command
+ ancontrol -i interface -M 0.
+
+ Don't add 8 in to flag; Ethereal currently doesn't support the full
+ Aironet header.
+
+ On FreeBSD 4.6 through 5.1, you should be able to capture in monitor
+ mode on 802.11 interfaces supported by the an driver, but not on any
+ other interfaces; see the instructions for FreeBSD 5.2 or later for
+ those cards.
+
+ In FreeBSD 4.5 and earlier, you will not be able to capture in monitor
+ mode on 802.11 interfaces (no drivers supported it prior to 4.5, and
+ in 4.5 the an driver had bugs that caused packets not to be captured
+ correctly).
+
+ Q 5.40: How do I capture on an 802.11 device in monitor mode on
+ NetBSD?
+
+ A: On NetBSD 2.0-beta and later, you should be able to capture in
+ monitor mode on 802.11 interfaces supported by the wi and acx drivers,
+ if Ethereal is linked with libpcap 0.8.1 or later. The instructions
+ are the same as for FreeBSD 5.2 and later.
+
+ Q 5.41: 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.
+
+ Q 5.42: 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 5.43: 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
(or the WinPcap driver, and the underlying OS networking code and
network interface drivers, on Windows) will allow it to capture.
- Unless the OS can be configured to supply packets with errors such as
+ 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 can be so
- configured, configure it if possible, and make whatever changes to
- libpcap and the packet capture program you're using are necessary to
- support capturing those packets.
-
- Q 5.25: How can I capture entire frames, including the FCS?
-
- A: Ethereal can't capture any data that the packet capture library -
+ 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.
+
+ 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).
+
+ 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 5.44: How can I capture entire frames, including the FCS?
+
+ 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
drivers, on Windows) will allow it to capture.
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 supply
- the FCS of a frame as part of the frame, 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 can be so
- configured, configure it if possible, and make whatever changes to
- libpcap and the packet capture program you're using are necessary to
- support capturing the FCS of a frame. Most if not all OSes probably do
- not support capturing the FCS of a frame on Ethernet, and probably do
- not support it on most other link-layer types.
-
- Q 5.26: Ethereal hangs after I stop a capture.
+ 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.
+
+ 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).
+
+ 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 5.45: Ethereal hangs after I stop a capture.
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
lookup to take a long time.
If you disable network address-to-name translation - for example, by
- turning off the `Enable network name resolution' option in the `Name
- resolution' options in the dialog box you get by selecting
- `Preferences' from the `Edit' menu - the lookups of the address won't
+ turning off the "Enable network name resolution" option in the "Name
+ resolution" options in the dialog box you get by selecting
+ "Preferences" from the "Edit" menu - 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
- using the `Save' button in that dialog box; note that this will save
+ using the "Save" button in that dialog box; note that this will save
all your current preference settings.
If Ethereal hangs when reading a capture even with network name
contains sensitive information (e.g., passwords), then please do not
send it.
- Q 5.27: How can I search for, or filter, packets that have a
- particular string anywhere in them?
-
- A: Currently, you can't.
-
- That's a feature that would be hard to implement in capture filters
- without changes to the capture filter code, which, on many platforms,
- is in the OS kernel and, on other platforms, is in the libpcap
- library.
-
- It would be easier to implement in display filters, but it hasn't been
- implemented yet. It would be best implemented as a display filter
- "string match" operator, which would let you check not only the entire
- packet for a string, but check portions of the packet for a string. It
- should probably not use a naive string matching mechanism, as there
- are mechanisms much faster than the naive one.
-
-
- Support can be found on the ethereal-users[AT]ethereal.com mailing
- list.
- For corrections/additions/suggestions for this page, please send email
- to: ethereal-web[AT]ethereal.com
- Last modified: Wed, March 05 2003.
+ Q 5.46: 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 would be hard to implement in capture filters without changes to
+ the capture filter code, which, on many platforms, is in the OS kernel
+ and, on other platforms, is in the libpcap library.
+
+ In releases prior to 0.9.14, you also can't search for, or filter,
+ packets containing a particular string even after you've captured
+ them.
+
+ In 0.9.14, you can search for, but not filter, packets that have a
+ particular string; this has been added to the "Find Frame" dialog
+ ("Find Frame" under the "Edit" menu, or control-F).
+
+ In 0.9.15 and later, you can search for those packets using either the
+ mechanism introduced in 0.9.14 or using the new "contains" operator in
+ filter expressions, which lets you search the entire packet or text
+ string or byte string fields in the packet; the "contains" operator
+ can also be used in expressions used to filter the display.
+
+ 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: Sat, September 25 2004.
git.samba.org / obnox / wireshark / wip.git / blobdiff