Basically you can configure the components to communicate via hostname or IP address, though you would need to determine which is more reliable for your needs:
- Using a Fully Qualified Domain Name (FQDN), resolved by DNS, would automatically cover any server IP Address changes that might occur. Of course, the DNS lookup performance for hostname -> IP Address resolution needs to be successful to avoid any communication delays.
- Using FQDN would be beneficial for setting up failover EM's where the FQDN lookup automatically handles the change in IP address at failover time. Alternatively a Virtual IP Address (VIP) approach could be used for that.
- A FQDN may not be appropriate if you have firewalls between components where only 1 specific NIC can be used to communicate between components, i.e. the IP Address of that NIC needs to be explicitly used.
- For EM->TIM communications, this setup requires IP Address use.