Connection reset by peer

Not really specific to IRC. When a connection is reset, i.e. terminated, by the peer (which is usually the accepting side of the connection, like an ircd) this error will be displayed.

A dutch "joke" on this, which is getting really old now, is quiting IRC with the message "Connection reset by appel" (because "appel" means "apple" and "peer", "pear").

"Peer" is an uncommon spelling of the common Norwegian male
name "Per" (remember Ibsen's "Peer Gynt"?). In
Norwegian IRC circles, this has led to a number of bad jokes, such as
these:

• "Sorry. Peer caught me." (rejoining IRC after being disconnected)
• "Does any of you know Peer's address?" (rejoining IRC after being disconnected one time too many)
• "Who is this Peer guy who doesn't want me to login to your box?"

The TCP error message for receiving a RST from the peer. The TCP close involves exchanges of FIN packets. But if a peer sends FIN, it must still be prepared to accept input from the local host (see TCP half-close). Thus, if the peer wishes the connection to end now, it can ReSeT it. Immediately afterwards, it can recycle all resources allocated to that connection -- the connection is now closed. The local host might as well do the same.

"Connection reset by peer" is the TCP/IP equivalent of slamming the phone back on the hook. It's more polite than merely not replying, leaving one hanging. But it's not the FIN-ACK expected of the truly polite TCP/IP converseur.