Have problem installing second Domino server

I’m trying to set up a second domino server via the remote console.

What makes this one slightly different is that the primary domino server that it needs to communicate with is hidden behind a firewall at another location.

During setup it always fails at 20% and says the remote server isn’t responding.

I have port 1352 open (as Notes clients communicate with the server all the time). Do I need a different port open on the firewall to allow my new secondary server to communicate with the primary server during set up?

Note: ICMP is disabled on the firewall(don’t know if that would affect install)