Disclaimer: the following guide is made to help clear up an honest mistake that a lobby leader may make, they typed the rcon incorrectly too many times and tf2center got banned from rcon access. Please have minor knowledge of rcon usage before attempting the guide. The following is a guide on how to use RCON http://forums.srcds....ewtopic/13192
So, TF2 will automatically ban any ip that attempts to use rcon and fails too many times. The default cooldown on this is 15 minutes. However, If you wish to fix this, you can do the following (as long as you actually DO have rcon access).
The following commands can be used in console or HLSW.
Method 1: Remove steamID rcon ban
rcon_address xxx.xxx.xxx.xxx | your Server IP
rcon_address xxx.xxx.xxx.xxx | your Server IP
rcon listip | this will print a list of ip's on the server ip filter list, find yours and make note of its id number
rcon removeip "id number"
Method 2 is the one that is more likely to work with tf2center. However try both if needed.