I have a couple of questions regarding Openfire S2S.
I have been referencing https://discourse.igniterealtime.org/t/server-to-server-howtos/49007 to set up S2S communication between 2 servers. In Walter’s How To, he mentions how the server name of the Openfire server needs to be a name resolvable by DNS. Is there a reason why this cannot just be an IP Address? I see that it’ll try to resolve the name through DNS, but I was just wondering for systems that do not have DNS.
Second, I have been working around this by modifying Windows hosts file to map an IP to a domain name and have gotten S2S communication to work. However, when configuring both servers with SSL, I begin to get some errors such as:
Can’t process DNS lookup!
javax.naming.CommunicationException: DNS error [Root exception is java.net.PortUnreachableException: ICMP Port Unreachable]; remaining name ‘_xmpp-server._tcp..’.
This could be related to the above.
Thanks in advance!
Configuring with SSL still has it functioning. This leads to a next question, what might cause the issues above?
The debug logs also show that it tries to create a socket connection, but there’s a connection timeout.
An exception occurred while trying to create a socket connection to XMPP domain ‘’ using remote host :5269
I can access the domain name perfectly fine and it is resolvable (through hosts file), but it seems to break here. The IPs are also NAT’d if that makes a difference.
Update - I have figured out the exception error, port 5269 was blocked on my end so the connection issue was happening through there.