$ sudo apt-get update
$ sudo apt-get install ircd-irc2 

ircd-irc2 is installed in your system.

Make ensure the ircd-irc2 package were installed using the commands given below,

$ sudo dpkg-query -l | grep ircd-irc2 *

You will get with ircd-irc2 package name, version, architecture and description in a table

ircd-irc2 package basic information: