IRC
One common usage is over Internet Relay Chat (IRC) via a BNC running on remote servers. In such an environment, where it is very easy to ascertain a user's IP address a BNC may help to hide the original connection source, as well as providing the opportunity for fun "vhosts" or "virtual hosts". The use of a vhost does not conceal the connection any better, but merely adds a statement as the hostname.
Many BNCs remain connected to an IRC server in the event the client should disconnect from the Internet. Often state changes are tracked so that they may be relayed to the client upon reconnection. Some implementations opt to store all messages sent across the network that the client would have normally received, and send them upon the clients reconnection; this is often considered to be much too resource dependent for commercial hosting services to provide. Other logging features and bot like functions may be included with various implementations but are not standard.
Example:
- User A logs onto IRC directly and appears as USER!user@users.reverse.dns
- User A logs onto IRC indirectly through a BNC and appears as USER!user@bnc.net
Read more about this topic: BNC (software)