STATS u|U

Usage: STATS u|U [<server>]

Uptime:
u - Shows how long the server has been running.

Unknown Connections:
U - See the IP addresses of the unknown connections to your server. Connections can be open for a variety of reasons. Most common is that the client is waiting for dns to happen. You can close these connections with the /close command.

Example:
/stats u webmaster.*
/stats U webmaster.*
/stats u
/stats U