Open your etc/hosts file and make an entry with your server name and IP address to be used for communication with STM Server.
Restart the agent service
Now you should see the linux server on the STM server.
You can also check the order of NIC priority by using this command
ip route list
The default one is used for communications. Anytime you can change it using ip route change default command. But i would suggest to do with your server administrator