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?
- 1.3 Are there any plans to support {your favorite protocol}?
+ 1.5 What protocols are currently supported?
- 1.4 Can Ethereal read capture files from {your favorite network
+ 1.6 Are there any plans to support {your favorite protocol}?
+
+ 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 fails with a number of "Output line too long." messages
followed by linker errors.
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
and/or why does Ethereal give me an error if I try to capture on that
interface?
- 5.5 I'm running on a UNIX-flavored OS; why does some network interface
- on my machine not show up in the list of interfaces in the
+ 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?
- 5.6 How do I put an interface into promiscuous mode?
+ 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.)?
- 5.7 I can set a display filter just fine, but capture filters don't
+ 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.
- 5.8 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.
- 5.9 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.
- 5.10 Why am I seeing lots of packets with incorrect TCP checksums?
+ 5.14 Why am I seeing lots of packets with incorrect TCP checksums?
- 5.11 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.
- 5.12 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.
- 5.13 When I run Ethereal on Windows NT, it dies with a Dr. Watson
+ 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.
- 5.14 When I try to run Ethereal, it complains about
+ 5.20 When I try to run Ethereal, it complains about
sprint_realloc_objid being undefined.
- 5.15 I'm running Ethereal on Linux; why do my time stamps have only
+ 5.21 I'm running Ethereal on Linux; why do my time stamps have only
100ms resolution, rather than 1us resolution?
- 5.16 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?
- 5.17 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.
- 5.18 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?
- 5.19 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.
- 5.20 I'm running Ethereal on Windows, and I'm not seeing any traffic
+ 5.26 I'm running Ethereal on Windows, and I'm not seeing any traffic
being sent by the machine running Ethereal.
- 5.21 I'm trying to capture traffic but I'm not seeing any.
+ 5.27 I'm trying to capture traffic but I'm not seeing any.
- 5.22 I have an XXX network card on my machine; if I try to capture on
+ 5.28 I have an XXX network card on my machine; if I try to capture on
it, my machine crashes or resets itself.
- 5.23 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.
- 5.24 Does Ethereal work on Windows Me?
+ 5.30 Does Ethereal work on Windows Me?
- 5.25 Does Ethereal work on Windows XP?
+ 5.31 Does Ethereal work on Windows XP?
- 5.26 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.
- 5.27 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?
- 5.28 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?
- 5.29 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?
- 5.30 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?
- 5.31 I'm trying to capture 802.11 traffic on Windows; why am I not
+ 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?
- 5.32 I'm trying to capture 802.11 traffic on Windows; why am I seeing
+ 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?
- 5.33 How can I capture packets with CRC errors?
+ 5.43 How can I capture packets with CRC errors?
- 5.34 How can I capture entire frames, including the FCS?
+ 5.44 How can I capture entire frames, including the FCS?
- 5.35 Ethereal hangs after I stop a capture.
+ 5.45 Ethereal hangs after I stop a capture.
- 5.36 How can I search for, or filter, packets that have a particular
+ 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?"
- A: There are currently 442 supported protocols and media, listed
+ If you mean "Can I use Ethereal as part of my commercial product?",
+ see the next entry in the FAQ.
+
+ 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 LAN Emulation
ATM OAM AAL
AVS WLAN Capture header
+ AX/4000 Test Block
Ad hoc On-demand Distance Vector Routing Protocol
Address Resolution Protocol
Aggregate Server Access Protocol
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
Async data over ISDN (V.120)
Authentication Header
BACnet Virtual Link Control
+ BEA Tuxedo
BSS GPRS Protocol
BSSAP/BSAP
Banyan Vines ARP
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
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
+ Compuserve GIF
Connectionless Lightweight Directory Access Protocol
Cross Point Frame Injector
- DCE DFS Calls
+ Cryptographic Message Syntax
DCE Distributed Time Service Local Server
DCE Distributed Time Service Provider
DCE Name Service
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 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
Diameter Protocol
Distance Vector Multicast Routing Protocol
Distcc Distributed Compiler
- Distributed Checksum Clearinghouse Prototocl
+ Distributed Checksum Clearinghouse Protocol
+ Distributed Network Protocol 3.0
Domain Name Service
Dynamic DNS Tools Protocol
Echo
Encapsulating Security Payload
+ Endpoint Name Resolution Protocol
Enhanced Interior Gateway Routing Protocol
EtherNet/IP (Industrial Protocol)
Ethernet
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
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
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 Relay Chat
Internet Security Association and Key Management Protocol
Internetwork Packet eXchange
+ JPEG File Interchange Format
Jabber XML Messaging
Java RMI
Java Serialization
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
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
MultiProtocol Label Switching Header
Multicast Router DISCovery protocol
Multicast Source Discovery Protocol
+ Multiprotocol Label Switching Echo
MySQL Protocol
NFSACL
NFSAUTH
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 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
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
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
T38
TACACS
TACACS+
+ TEI Management Procedure, Channel D (LAPD)
TEREDO Tunneling IPv6 over UDP through NATs
TPKT
Tabular Data Stream
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
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
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 analyzer.
+ 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.
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
problem; upgrade to a later version of automake (1.6 or later).
Q 4.3: The link fails with a number of "Output line too long."
- messages followed by linker errors.
+ 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 4.4: 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,
mentioned.)
Q 4.5: The build fails on Windows because of conflicts between
- winsock.h and winsock2.h.
+ 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.
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;
- * the "Switch Port-Mirroring" section of chapter 6 of documentation
- from Extreme Networks for their Summit 200 switches;
- * the documentation on "Configuring Port Mirroring and Monitoring"
- in Foundry Networks' documentation for their FastIron Edge
- Switches;
- * the documentation on "Configuring Port Mirroring and Monitoring"
- in Foundry Networks' documentation for their BigIron MG8 Layer 3
- Switches;
- * the "Port Monitor" subsection of the "Status Monitor and
- Statistics" section of the documentation from Foundry Networks for
- their EdgeIron 4802F and 10GC2F switches;
- * the "Configuring Port Mirroring" section of chapter 3 of the
- documentation from Foundry Networks for their EdgeIron 24G,
- 2402CF, and 4802CF switches;
- * the documentation on "Configuring Port Mirroring and Monitoring"
- in Foundry Networks' documentation for their other switches and
- metro routers.
+ 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
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?
+ 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
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 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.
+ 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
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
+ 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 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
above, and also indicate that the problem occurs with WinDump, not
just with Ethereal.
- Q 5.5: I'm running on a UNIX-flavored OS; why does some network
- interface on my machine not show up in the list of interfaces in the
- "Interface:" field in the dialog box popped up by "Capture->Start",
- and/or why does Ethereal give me an error if I try to capture on that
- interface?
+ Q 5.5: 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
above, and also indicate that the problem occurs with tcpdump not just
with Ethereal.
- Q 5.6: How do I put an interface into promiscuous mode?
+ 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.
I.e., this is probably the same question as this earlier one; see the
response to that question.
- Q 5.7: I can set a display filter just fine, but capture filters don't
- work.
+ 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 5.8: 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 5.9: 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 5.10: 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 5.11: 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 5.12: When I run Ethereal on Solaris 8, it dies with a Bus Error
+ 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
Similar problems may exist with older versions of GTK+ for earlier
versions of Solaris.
- Q 5.13: When I run Ethereal on Windows NT, it dies with a Dr. Watson
+ 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.
VGA driver; if that's not the correct driver for your video card, try
running the correct driver for your video card.
- Q 5.14: When I try to run Ethereal, it complains about
+ 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
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 5.15: I'm running Ethereal on Linux; why do my time stamps have only
+ 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 5.16: 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 WinPcap
3.0.
- Q 5.17: 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 5.18: 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 5.19: 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 5.20: I'm running Ethereal on Windows, and I'm not seeing any
+ 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
requested that the interface run promiscuously; try turning
promiscuous mode off.
- Q 5.21: I'm trying to capture traffic but I'm not seeing any.
+ 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
Otherwise, on Windows, see the response to this question and, on a
UNIX-flavored OS, see the response to this question.
- Q 5.22: I have an XXX network card on my machine; if I try to capture
- on it, my machine crashes or resets itself.
+ 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 5.23: 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 5.24: 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
of Ethereal as well.
- Q 5.25: 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 5.26: 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 5.27: 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
Messenger packets (even if the TCP segment also contains the beginning
of another Yahoo Messenger packet).
- Q 5.28: 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.
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 5.29: 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 5.30: How can I capture raw 802.11 packets, including non-data
- (management, beacon) packets?
-
- A: That would require that your 802.11 interface run in the mode
- called "monitor mode" or "RFMON mode". Not all operating systems
- support that and, even on operating systems that do support it, not
- all drivers, and thus not all cards, support it.
+ 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
for a long time trying to resolve the name because it will not be able
to communicate with any DNS or NIS servers.
- 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.
+ There are FAQ items below with information on capturing in monitor
+ mode on Linux, FreeBSD, and NetBSD.
- On FreeBSD, the ancontrol utility must be used. The command
+ 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.
-ancontrol -i anN -M flag
+ 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.
- is used to enable or disable monitor mode. If flag is 0, monitor mode
- will be turned off; otherwise, 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).
+ Q 5.38: How do I capture on an 802.11 device in monitor mode on Linux?
- Don't add 8 in; Ethereal currently doesn't support the full Aironet
- header.
+ 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.
- On Linux with the driver in the 2.4.6 through 2.4.19 kernel, 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 rather
- than just the BSS with which the card is associated, do
-
-echo "Mode: y" >/proc/driver/aironet/ethN/Config
-
- and to return to the normal mode, do
+ Cisco Aironet cards:
-echo "Mode: ess" >/proc/driver/aironet/ethN/Config
+ 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
dependency checking so that they will install Ethereal even though a
newer version of libpcap is installed.
- 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):
+ 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-pre6 or later version of the linux-wlan-ng
drivers (see the linux-wlan page, and the linux-wlan-ng tarball
- directory).
+ directory), or with the hostap driver for Prism II/2.5/3.
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
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.
- You may have to run a command to put the interface into monitor mode,
- or to change other interface settings, and you might have to capture
- on a wlanN interface rather than a ethN interface, in order to capture
- raw 802.11 packets. The interface settings are available in your
- wlan-ng.conf file. See the wlan-ng FAQ for additional information.
-
- On other platforms, capturing raw 802.11 packets on Prism II cards is
- not currently supported.
+ 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, there are patches on the Orinoco Monitor Mode Patch
- Page that should allow you to do capture raw 802.11 packets. You will
- have to determine which version of the driver you have, and select the
- appropriate patch.
+ 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.
Note that the page indicates that not all versions of the Orinoco
firmware support this patch. It says, for some versions of the patch,
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 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.
-
- On other platforms, capturing raw 802.11 packets on Orinoco cards is
- not currently supported.
-
- Cards with the Atheros Communications AR5000 or AR5001 chipsets:
-
- You can capture raw 802.11 packets with AR5K cards on Linux systems
- with the v5_ar5k drivers. You will need the Linux wireless-tools
- version 25 or higher to put the card into monitor mode.
+ 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:
with the ACX100 OSS drivers available from the ACX100 wireless network
driver project SourceForge site.
- Other 802.11 interfaces:
+ With that driver:
- 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.
+ 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.
- On platforms that don't allow Ethereal to capture raw 802.11 packets,
- the 802.11 network will appear like an Ethernet to Ethereal.
+ Cards with Atheros Communications chipsets:
- Q 5.31: I'm trying to capture 802.11 traffic on Windows; why am I not
- seeing any packets?
+ 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
Ethernet traffic and won't include any management or control frames,
but that's a limitation of the card drivers.
- Q 5.32: I'm trying to capture 802.11 traffic on Windows; why am I
+ 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?
+ but not packets sent by that machine?
A: This appears to be another problem with promiscuous mode; try
turning it off.
- Q 5.33: How can I capture packets with CRC errors?
+ 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
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 5.34: How can I capture entire frames, including the FCS?
+ Q 5.44: How can I capture entire frames, including the FCS?
- A: Ethereal can't capture any data that the packet capture library -
+ 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
thinks there is, will display it as such, and will check whether it's
the correct CRC-32 value or not.
- Q 5.35: Ethereal hangs after I stop a capture.
+ 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
contains sensitive information (e.g., passwords), then please do not
send it.
- Q 5.36: How can I search for, or filter, packets that have a
- particular string anywhere in them?
+ 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
string or byte string fields in the packet; the "contains" operator
can also be used in expressions used to filter the display.
-
- 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: Fri, December 12 2003.
+ 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