Internet Relay Chat (IRC)

(from RFC 1459) The IRC (Internet Relay Chat) protocol has been designed over a number of years for use with text based conferencing.

The IRC protocol has been developed on systems using the TCP/IP network protocol, although there is no requirement that this remain the only sphere in which it operates.

IRC itself is a teleconferencing system, which (through the use of the client-server model) is well-suited to running on many machines in a distributed fashion. A typical setup involves a single process (the server) forming a central point for clients (or other servers) to connect to, performing the required message delivery/multiplexing and other functions.


The IRC protocol began development in 1989 and was first implemented as a means for users on a BBS to chat amongst themselves. Now it supports a large number of world-wide network sof servers and clients, and is stringing to cope with growth. The average number of users connected to IRC networks has continuously grown since 1989 at an alarming rate.

Protocol dependencies

Example traffic

XXX - Add example traffic here (as plain text or Wireshark screenshot).


The IRC dissector is not in the latest public build. Also add info of additional Wireshark features where appropriate, like special statistics of this protocol.

Preference Settings

(XXX add links to preference settings affecting how IRC is dissected).

Example capture file

XXX - Add a simple example capture file to the SampleCaptures page and link from here (see below). Keep this file short, it's also a good idea to gzip it to make it even smaller, as Wireshark can open gzipped files automatically.

Display Filter

A complete list of IRC display filter fields can be found in the display filter reference

Capture Filter

You cannot directly filter IRC protocols while capturing. However, if you know the TCP port used (see above), you can filter on that one.


Ctcp, subfilter or another filter? Dcc? Subfilter or normal filter? Irc over ssl needs a mention.

IRC (last edited 2008-04-12 17:50:23 by localhost)