I’m trying to setup SSO for a TS application, and it’s getting an error message saying " The WebNetwork Server returned the following error: Access denied for the client: 10.101.100.23". That IP address is the address of the TS that I’m trying to run the application on. Is there somewhere on the internal relay where I have to setup access for this TS?

Starting with 5.3 the soap connection was locked down. 

Check your c:\stoneware\webapps\axis\web-inf\allowhosts file and make sure the ip address of the ts server is in there. 
If not, add it, save, shut down and start back up. 

In 6.0 and higher it is in c:\stoneware\config\allowhosts