Redirect Base on Incoming Ip

I know this is possible because I saw servers do this before. But how to make it so when someone connects with a different ip, it redirects them to the hub server.

Lets Say
when someone connects using: sg.wolf-craft.pwnz.org, take them to the survival games server.
when someone connects using: play.wolf-craft.pwnz.org/hub.wolf-craft.pwnz.org, take them to the hub
and so on