I have a remote headless system (running bullseye, will be updating to bookworm when I'm next there) that can connect to some systems using ssh but not to others (to which I can connect from everywhere else).
It also can't ping the systems which it can't connect ssh to. I can't see any pattern in the systems to which it can connect or those which it can't connect to. It's connected via 4G so it's CGNATted. I connect to it (using ssh) via a remote ssh tunnel that it sets up when booted. It gets the correct IP address for all 'my' systems that run an ssh server and I can cannect to all these systems from my home desktop and laptop machines using ssh. Does anyone have any ideas on how to diagnose its failure to connect to all of 'my' systems. -- Chris Green
