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!
Edit:
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!
Edit 2:
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
129.26.68.74 blubb # I added this!
-
sudo service ufw status # yields: ufw start/running
I installed 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?
telnet machine G 22
andtelnet machine K 22
if one of them is time out then look at sshd, name resolution or firewall. one of those thing could be wrong.ping
?ping
is succesful in both directions.telnet <machineK> 22
from machin G which resulted inTrying 129.26.67.114...
and then intelnet: Unable to connect to remote host: Connection timed out
. But telnet the other way around worked just fine! Any next steps? Thanks for your support, by the way. :-)