Trying to add agent behind firewall using another agent as proxy

[cmorg]

As the title says really.
I have a working agent (AGENT1) at a remote site, with EnableProxy = yes & EnableSNMPProxy = yes. Zoning is enabled on the server and the node I am trying to get connected (AGENT2) is inside its own zone, with the working agent set as all of the proxies.

When I try to poll the status of AGENT2, I get this in the console...

[07.10.2016 10:27:29] **** Poll request sent to server ****
[07.10.2016 10:27:29] Poll request accepted
[07.10.2016 10:27:29] Starting status poll for node AGENT2
[07.10.2016 10:27:29]    Starting status poll on interface unknown
[07.10.2016 10:27:29]      Current interface status is UNKNOWN
[07.10.2016 10:27:29]      Starting ICMP ping via proxy
[07.10.2016 10:27:30]      Interface is UNKNOWN for 198 polls (1 poll required for status change)
[07.10.2016 10:27:30]      Interface status after poll is UNKNOWN
[07.10.2016 10:27:30]    Finished status poll on interface unknown
[07.10.2016 10:27:30] Node is still unreachable
[07.10.2016 10:27:30] Finished status poll for node AGENT2
[07.10.2016 10:27:30] Node status after poll is CRITICAL
[07.10.2016 10:27:30] **** Poll completed successfully ****

Started nxagentd on AGENT2 in debug mode, but nothing happens after saying press ESC to exit.
Started nxagentd on AGENT1 in debug mode shows activity. When I poll the status of AGENT2, I see it trying to ping AGENT2...

Requesting parameter "Icmp.Ping(<AGENT2 IP Address>)"

but responding almost instantly with

GetParameterValue(): result is 404 (UNKNOWN_PARAMETER)

Any ideas why this is happening, or what I may be doing wrong?
Cheers

[cmorg]

So I managed to get a connection, by using the FQDN instead of static IP in the node's properties.

Strange.