$Id: README,v 1.45 2000/10/08 17:16:29 gerald Exp $ General Information ------- ----------- Ethereal is a network traffic analyzer, or "sniffer", for Unix and Unix-like operating systems. It uses GTK+, a graphical user interface library, and libpcap, a packet capture and filtering library. The Ethereal distribution also comes with Tethereal, which is a line-oriented sniffer (similar to Sun's snoop, or tcpdump) that uses the same dissection, capture-file reading and writing, and packet filtering code as Ethereal, and with editcap, which is a program to read capture files and write the packets from that capture file, possibly in a different capture file format, and with some packets possibly removed from the capture. The official home of Ethereal is http://www.ethereal.com The latest distribution can be found in the subdirectory http://www.ethereal.com/distribution Installation ------------ Ethereal is known to compile and run on the following systems: - Linux (2.0.x, 2.1.x, 2.2.x, 2.3.x, 2.4.x) - Solaris (2.5.1, 2.6, 7) - FreeBSD (2.2.5, 2.2.6, 3.1, 3.2, 3.3) - Sequent PTX v4.4.5 (Nick Williams ) - Tru64 UNIX (formerly Digital UNIX) (3.2, 4.0) - Irix (6.5) - AIX (4.3.2, with a bit of work) - Win32 (NT, 98) It should run on other Unix-ish systems without too much trouble. NOTE: the Makefile appears to depend on GNU "make"; it doesn't appear to work with the "make" that comes with Solaris 7 nor the BSD "make". Perl is also needed to create the man page. If you decide to modify the yacc grammar or lex scanner, then you need "flex" - it cannot be built with vanilla "lex" - and either "bison" or the Berkeley "yacc". Your flex version must be 2.5.1 or greater. Check this with 'flex -V'. If you decide to modify the NetWare Core Protocol dissector, you will need python, as the data for packet types is stored in a python script, ncp2222.py. You must therefore install Perl, GNU "make", "flex", and either "bison" or Berkeley "yacc" on systems that lack them. Full installation instructions can be found in the INSTALL file. See also the appropriate README. files for OS-specific installation instructions. Usage ----- In order to capture packets from the network, you need to be running as root, or have access to the appropriate entry under /dev if your system is so inclined (BSD-derived systems, and systems such as Solaris and HP-UX that support DLPI, typically fall into this category). Although it might be tempting to make the Ethereal executable setuid root, please don't - alpha code is by nature not very robust, and liable to contain security holes. Please consult the man page for a description of each command-line option and interface feature. Multiple File Types ------------------- The wiretap library is a packet-capture library currently under development parallel to ethereal. In the future it is hoped that wiretap will have more features than libpcap, but wiretap is still in its infancy. However, wiretap is used in ethereal for its ability to read multiple file types. You can read the following file formats: libpcap (tcpdump -w, Ethereal) Sniffer (compressed and uncompressed) NetXray Sniffer Pro snoop atmsnoop Shomiti LANalyzer Microsoft Network Monitor AIX's iptrace RADCOM's WAN/LAN Analyzer Lucent/Ascend access products HP-UX's nettl Toshiba's ISDN routers ISDN4BSD "i4btrace" utility Cisco Secure Intrustion Detection System iplogging facility pppd logs (pppdump-format files) In addition, it can read gzipped versions of any of these files automatically, if you have the zlib library available when compiling Ethereal. Ethereal needs a modern version of zlib to be able to use zlib to read gzipped files; version 1.1.3 is known to work. Versions prior to 1.0.9 are missing some functions that Ethereal needs and won't work. "./configure" should detect if you have the proper zlib version available and, if you don't, should disable zlib support. You can always use "./configure --disable-zlib" to explicitly disable zlib support. Although Ethereal can read AIX iptrace files, the documentation on AIX's iptrace packet-trace command is sparse. The 'iptrace' command starts a daemon which you must kill in order to stop the trace. Through experimentation it appears that sending a HUP signal to that iptrace daemon causes a graceful shutdown and a complete packet is written to the trace file. If a partial packet is saved at the end, Ethereal will complain when reading that file, but you will be able to read all other packets. If this occurs, please let the Ethereal developers know at ethereal-dev@zing.org, and be sure to send us a copy of that trace file if it's small and contains non-sensitive data. Support for Lucent/Ascend products is limited to the debug trace output generated by the MAX and Pipline series of products. Ethereal can read the output of the "wandsession" "wandisplay", "wannext", and "wdd" commands. For detailed information on use of these commands, please refer the following pages: "wandsession", "wandisplay", and "wannext" on the Pipeline series: http://aos.ascend.com/aos:/gennavviewer.html?doc_id=0900253d80006c79 "wandsession", "wandisplay", and "wannext" on the MAX series: http://aos.ascend.com/aos:/gennavviewer.html?doc_id=0900253d80006972 "wdd" on the Pipeline series: http://aos.ascend.com/aos:/gennavviewer.html?doc_id=0900253d80006877 Ethereal can also read dump trace output from the Toshiba "Compact Router" line of ISDN routers (TR-600 and TR-650). You can telnet to the router and start a dump session with "snoop dump". To use the Lucent/Ascend and Toshiba traces with Ethereal, you must capture the trace output to a file on disk. The trace is happening inside the router and the router has no way of saving the trace to a file for you. An easy way of doing this under Unix is to run "telnet | tee ". Or, if your system has the "script" command installed, you can save a shell session, including telnet to a file. For example, to a file named tracefile.out: $ script tracefile.out Script started on $ telnet router ..... do your trace, then exit from the router's telnet session. $ exit Script done on IPv6 ---- If your operating system includes IPv6 support, ethereal will attempt to use reverse name resolution capabilities when decoding IPv6 packets. If you want to turn off name resolution while using ethereal, start ethereal with the "-n" option. If you would like to compile ethereal without support for IPv6 name resolution, use the "--disable-ipv6" option with "./configure". If you compile ethereal without IPv6 name resolution, you will still be able to decode IPv6 packets, but you'll only see IPv6 addresses, not host names. NetWare Core Protocol --------------------- There are over 400 different NCP packet types. The NCP dissector does not understand all of these; support is being added little by little. If you have some NCP packets that are not dissected by Ethereal, send a trace file to ethereal-dev@zing.org and if possible, we will add support for those packets types. SNMP ---- Ethereal can do some basic decoding of SNMP packets; it can also use an external SNMP library to do more sophisticated decoding.. The configure script will automatically determine which library you have on your system and will use it. If you have an SNMP library but _do not_ want to have ethereal use it, you can run configure with the "--disable-snmp" option. How to Report a Bug ------------------- Ethereal is still under constant development, so it is possible that you will encounter a bug while using it. Please report bugs to ethereal-dev@zing.org. Be sure you tell us: 1) Operating System and version (the command 'uname -sr' may tell you this, although on Linux systems it will probably tell you only the version number of the Linux kernel, not of the distribution as a whole; on Linux systems, please tell us both the version number of the kernel, and which version of which distribution you're running) 2) Version of GTK+ (the command 'gtk-config --version' will tell you) 3) Version of Ethereal (the command 'ethereal -v' will tell you, unless the bug is so severe as to prevent that from working, and should also tell you the versions of libraries with which it was built) 4) The command you used to invoke Ethereal, and the sequence of operations you performed that caused the bug to appear If the bug is produced by a particular trace file, please be sure to send a trace file along with your bug description. Please don't send a trace file greater than 1 MB when compressed. If the trace file contains sensitive information (e.g., passwords), then please do not send it. If Ethereal died on you with a 'segmentation violation', 'bus error', 'abort', or other error that produces a UNIX core dump file, you can help the developers a lot if you have a debugger installed. A stack trace can be obtained by using your debugger ('gdb' in this example), the ethereal binary, and the resulting core file. Here's an example of how to use the gdb command 'backtrace' to do so. $ gdb ethereal core (gdb) backtrace ..... prints the stack trace (gdb) quit $ The core dump file may be named "ethereal.core" rather than "core" on some platforms (e.g., BSD systems). If you got a core dump with Tethereal rather than Ethereal, use "tethereal" as the first argument to the debugger; the core dump may be named "tethereal.core". Disclaimer ---------- There is no warranty, expressed or implied, associated with this product. Use at your own risk. Gerald Combs Gilbert Ramirez Guy Harris