Hi,

I've got OpenSSH setup on 2 machines NATed behind 1 router. The router has a static IP and forwards to either of the machines depending on the port used.

eg. slogin yogaboy@xxx.xxx.xxx.xxx -i ~/.ssh/id_rsa_machine1 -p 9000
will go to machine 1
slogin yogaboy@xxx.xxx.xxx.xxx -i ~/.ssh/id_rsa_machine2 -p 9001
will go to machine 2


Unfortunately, the xxx.xxx.xxx.xxx IP address is listed in known_hosts with the key for machine 1, so I can connect to machine 1 ok, but when I connect to machine 2 it obviously returns a different host key than the one listed in known_hosts for that IP.

Any idea how I can list both machines in known_hosts? The only other idea I have is to get the host key from machine 1 and use it on machine 2 as well. I'd prefer not, as it's a blatant hack and would prefer a more standard solution. Else I have to alter known_hosts each time.

Any help is much appreciated.

You might try putting the hostnames of the computers in your hosts file. Then call ssh using the hostname instead.
This should give you separate entries in the known_hosts file.

You will need to keep the hosts file updated if you don't have a static address of course.

thanks.

I've found 2 other methods as well. One is here http://marc2.theaimsgroup.com/?l=sec...9665608624&w=2

you basically add extra entries for each host in the ssh_config file, more general last. I didn't know that could be done.

I noticed that the hostname wasn't being recorded in my known_hosts file, so I've added the host, the fqdn, the ip and the local ip all seperated by commas to both entries and now I'm having no problem

eg
machine1,machine1.example.com,xxx.xxx.xxx.xxx,192.168.0.2 keyhere....
machine2,machine2.example.com,same.ip.as.above,192.168.0.3 keyhere....

Hope this all helps someone. Thanks for the input jschiwal, I appreciate it.

I usually access my disktop with "ssh matrix". Before I wrote the message, I tried "ssh matrix.jesnet". This added a separate line in my ~/ssh/.known_hosts file, even though the key was the same.