usrip [<nickname> [<nickname> …] [-cmd <command>]]

This usrip command is identical to the userhost command except that the server will return the dotted-quad address (ie, 127.0.0.1) instead of the Fully Qualified Host Name (FQHN, ie, “irc.acronet.net”).

This command is available on VERY OLD hybrid servers, and possibly other (unknown to me) servers based on very old hybrid versions. It is better to try using the USERIP command first.