Cant change ssh port Ubuntu 20.04

I have no idea what should come after #9 in this list. You could go back to port 22 and check.

Your others could be on a different network. But, I haven’t used CFS in years so I don’t know what’s going on with that end.

I know at one point CFS used some sort of masquerading. Shut down the firewall and I’d lose ALL connectivity.

hermit@~:traceroute -p 22 jv80.se 
traceroute to jv80.se (184.174.32.123), 30 hops max, 60 byte packets
 1  _gateway (192.168.0.1)  0.961 ms  0.882 ms  0.827 ms
 2  syn-142-254-157-021.inf.spectrum.com (142.254.157.21)  20.619 ms  20.710 ms  20.658 ms
 3  * * *
 4  lag-25.pltsohae01r.netops.charter.com (24.33.103.230)  13.926 ms  13.877 ms  13.962 ms
 5  lag-30.rcr01clmkohpe.netops.charter.com (65.29.1.40)  16.656 ms  18.128 ms lag-25.rcr01clmkohpe.netops.charter.com (65.29.1.28)  19.955 ms
 6  lag-415-10.chctilwc00w-bcr00.netops.charter.com (66.109.6.54)  26.984 ms lag-25-10.chctilwc00w-bcr00.netops.charter.com (107.14.17.252)  26.710 ms *
 7  ae13.edge2.chi10.sp.lumen.tech (4.68.37.137)  30.182 ms  30.511 ms  30.431 ms
 8  * ae1.3107.edge6.dus1.neo.colt.net (171.75.9.193)  121.685 ms *
 9  giga-hostin.ear2.dusseldorf1.level3.net (62.67.20.82)  121.587 ms  123.008 ms giga-hostin.edge6.dusseldorf1.level3.net (62.67.22.194)  128.468 ms
10  * * *
11  * jv80.se (184.174.32.123)  122.426 ms *

It is possible that #10 is a firewall appliance.

I use the default Firewalld and changing ports was not an issue.

Well, if you were already back on port 22 my checks above were bound to fail. It appears possible, per some random website that showed up in search, to run both. Might be a good idea to get this sorted.
https://www.simplified.guide/ssh/run-multiple-ports

What is the gain with that. If 22 is open anyway why change to another, security is not better. But anyway, I use keypair and passphrase so security is ok anyway. Just cant understand what happens.

The gain is only trouble shooting. If both are open you have access on the normal port while figuring out why the other doesn’t work.

well I increased security some after your last post. 22 is now only reachable from my office ip so with that, keypair and passphrase plus a strict fw I feel quite ok. At least no rush to solve whatever is the problem. The ISP has no FW

The only references I saw for adding a port was command line editing and restarting CSF. Seems easy enough. :wink:

To open a port you just add it in csf.conf and restart the fw. But it is added there but it does not help and even if I disable the firewall it does not work so I will leave it. Just waste of time