Fedora 9 and Suse 11.0 ssh do not work together

[Dave Feustel]

On Tue, Apr 21, 2009 at 11:28:43AM -0400, Todd Denniston wrote:
> Dave Feustel wrote, On 04/20/2009 06:32 PM:
>> I am running 32-bit fedora 9 and 64-bit Suse 11.0 and 64-bit OpenBSD 4.4
>> on a local net. Ssh does not work between F9 and Suse 11.0. Ssh
>> from f9 to Suse times out. An ssh connection from Suse to F9 is refused
>> by F9. Ssh from F9 to OpenBSD works. Ssh from OpenBSD to Suse times out
>> at login. SSh from OpenBSD to F9 is denied (publickey,gssapi-with-mic).
>>
>> I was surprised that these 3 system do not talk to each other with their
>> default config files. Is there a common set of config files with which
>> all ssh connections work?
>>
>> Thanks.
>>
>
> Is there a firewall installed on the SUSE machine?

Yes there is, but I did not initially understand that to be the case.

> Is the firewall setup to pass SSH?

It is now via Yast.

> Are you sure you get "(publickey,gssapi-with-mic)" when going from BSD to F9?
> Because this message would indicate that you are not using the "default 
> config file" on F9, it would also indicate that the F9 firewall is not 
> blocking incoming SSH connections, but you should be getting the same 
> message when going from SUSE to F9.

One of the puzzles (which I still do not fully understand) is that ssh
outgoing connections to OpenBSD worked but ssh connections in the
reverse direction did not work.

>
> BTW (publickey,gssapi-with-mic) means that the sshd on the machine being  
> connected TO has been configured to only allow connections authenticated 
> with one of publickey or gssapi-with-mic methods.
>
> Also by default Fedora, and probably other distros, usually setup their  
> firewalls to block connections to all privileged ports and allow the  
> administrator to pick which ports they want to have open, so the install 
> is more secure from the start.

Yes. I came from OpenBSD and am a complete Linux newbie, so I had an
incorrect understanding of the Linux firewall setup and didn't realize
it. That was a biggie.