Red interface connectivity issue

NethServer Version: 7.7.1908
Module: your_module ALL

Some diagnostic assistance please folks. I have about 3 nethserver instances (VMs) sat behind an internet router and one of them (unfortunately the one that actually does something useful - i.e. email) is showing connectivity issues… I have run nmap and it can just about detect that the host is up but nothing more (the other nethservers through the same internet router, same config etc display their open ports etc)

So as it stands i cant connect port 980 from internet and email works but is quite flakey… any tools, techniques, methods that would assist locating/diagnosing the issue would be appreciated (i will seperately look at migrating the email/sogo config off this server because this fixing this is taking too much time!)

thanks for any assistance

ok having looked through anything that could possibly be causing an issue i have discovered that the public ip of my home as well as the public ip of the nethserver (remote network) were both in the banned ip list on nethserver - im a little troubled that the nethservers own public IP made it into that list - is that indicative of anything mallicious?!?.. after removing these IPs from the list I am able to operate again (access email and connect to admin console)