I doubt you will be able to return by resetting your IP. Most bans are done by your Steam ID which is assigned to you across all Valve games. You can't change your Steam ID(unless you buy another copy of the game with a new account) so unless it was a temporary ban you will not be able to return unless it is reversed by an admin or OP. It would probably be best to see if there's a website associated with the server in which you can go to and request to be unbanned. If that is not possible you could maybe send someone else to go on the server and request it for you. Hope this helps.
Edit. Forgot to mention you can find your Steam ID by going into any server and typing Status into the console. It should look something like STEAM_X:X:XXXXXXX. (X=number) If your able to request to be unbanned they will need it to do so.