I have a remote dedicated server. It is running the newest Debian stable. Having had it running for quite a while, I finally decided to reboot it so it could run on a newer kernel. However, since rebooting, I have been unable to connect via ports 22, 80 and 443. The server responds to ping. SSH error message:
Connection timed out.
Fortunately, the data centre where it is located has a rescue system, that I have used - albeit in vain - to fix this problem. After looking through
auth.log, it is clear that
sshd is started by
systemd correctly, and appears to be listening on port 22 as expected.
Mar 3 09:28:48 server sshd: Server listening on 0.0.0.0 port 22. Mar 3 09:33:55 server sshd: Received signal 15; terminating.
Yet somehow, I am unable to access it remotely. Most issues I look for of this sort are about
sshd not starting at all, but that does not appear to be the case. I am able to access the rescue system without problem remotely, so the issue is not on my end. I wonder if there are perhaps some firewall services, that I am unaware of that might have been installed. Or some
sshd settings to be wary of.
For the record, here is my
sshd_config with all comments removed:
Port 22 ListenAddress 0.0.0.0 Protocol 2 HostKey /etc/ssh/ssh_host_rsa_key HostKey /etc/ssh/ssh_host_dsa_key SyslogFacility AUTH LogLevel INFO LoginGraceTime 120 PermitRootLogin no StrictModes yes PubkeyAuthentication yes IgnoreRhosts yes HostbasedAuthentication no PermitEmptyPasswords no ChallengeResponseAuthentication no PasswordAuthentication no PrintMotd no PrintLastLog yes TCPKeepAlive yes AcceptEnv LANG LC_* Subsystem sftp /usr/lib/openssh/sftp-server UsePAM yes UseDNS no
Since it also appears to be a problem for port 80 and 443, I wonder whether it is a more general problem, but at least if I could get SSH to work, I would be able to perhaps fix those problems as well.