I have two Ubuntu machines. Both have openssh-client and openssh-server installed on them. ssh-ing from machine G (fresh Ubuntu 11.10 installation) to machine K works great. But ssh-ing from machine K to machine G results always in the Error:
Connect to host some_hostname port 22: Connection timed out
I went through the troubleshooting section of help.ubuntu.com and I got the following results:
ps -A | grep sshd # results in 848 ? 00:00:00 sshd
sudo ss -lnp | grep sshd # results in 0 128 :::22 :::* users:(("sshd",848,4)) 0 128 *:22 *:* users:(("sshd",848,3))
ssh -v localhost # works!
sudo ufw status verbose # yields: "Status: inactive"
I haven't changed anything in the config file. What can I do to locate the problem and solve it? I would appreciate any hint!
ping was succesful in both directions!
I did a
telnet <machineK> 22 from machine G which resulted in trying and then in telnet:
Unable to connect to remote host: Connection timed out.
But telnet the other way around worked just fine!
ssh start/running, process 966 # yields: ssh start/running, process 966 /etc/hostname # contains my hostname, let's call it blubb /etc/hosts # contains the following 127.0.0.1 localhost # 127.0.1.1 blubb 188.8.131.52 blubb # I added this!
sudo service ufw status # yields: ufw start/running
Gufw and set it to
ON. Then I selected from
Incoming the option
ALLOW. Then I ssh'ed to another machine from where I ssh'ed back to my machine. Still the same error as above:
connect to host blubb port 22: Connection timed out
Any more hints, what I can check?