ssh ports and iptables

mjmwired · 08-09-2006, 08:24 PM

A quick question to the experts:

How do I run ssh on 2 ports and have each port restricted to a different network? Example:

ssh port 22: open to only 192.168.0.xxx
ssh port 45555: public internet

Thanks.

w3bd3vil · 08-09-2006, 08:32 PM

iptables -A INPUT -p tcp -s ! 192.168.0.0/24 --dport 22 -j REJECT
I think this command would be sufficient, cause you wouldnt mind if a local lan ip connected on 45555

how to run ssh on two ports?
edit the /etc/ssh/sshd_config
you will see the port number hashed out, remove the hash. Next, add a new line and change the port number to 45555.
It should look like this
Port 22
Port 45555

scott2004 · 08-09-2006, 10:35 PM

Don't forget to configure your firewall to allow TCP connections on 4555 since this is not the default port for sshd and the firewall won't have a rule allowing it.

Plus, you'll need to issue this command as root each time after a reboot:

iptables -A INPUT -p tcp -s ! 192.168.0.0/24 --dport 22 -j REJECT

unless you add it to an rc.local script or custom firewall script.