User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:48.0) Gecko/20100101 Firefox/48.0 Build ID: 20160726073904 Steps to reproduce: I used to have a ZNC launched on people.mozilla.org, listening on port 54324. I would then configure irccloud to connect to it. Actual results: Since one or two days, it seems this port can't be accessed from the outside anymore. I can still telnet to it from the server itself (via ssh), but not from the outside. Expected results: This custom port that I configured ZNC to listen to used to work perfectly, until a couple of days ago.
Had a quick peek on people.mo to see if this was host-based firewall related. Appears to not be the case, host has a pretty open INPUT chain with a default ACCEPT policy. Also checked netstat, only IPv6 listening on 54324... $ netstat -tuna | grep 54324 tcp6 0 0 :::54324 :::* LISTEN
302 to :digi for znc expectations on people.mo
If its listening on tcp6 only this will prevent it from working. Can you configure znc to only use ipv4?
Thanks for the investigation! It seems it was configured to listen on both ipv4 and ipv6, and thus only listened for real on ipv6?