Apparently my employer now blocks traffic on port 22 (though 21 is still open, go figure...). Is there a way to make SSH listen on an additional port?

Running RHE3/CPanel

You can change the port ssh listens on in the config file /etc/ssh/sshd_config.

Change:

to whatever port you want it to listen on.

Or you could DNAT the connection with iptables:

This would forward ssh connections on port 5555 to port 22 on the localhost.

Hmmm...I think I may have mucked it up lol.

Being afraid that some CPanel scripting might use SSH, I opted to try the DNAT option, Sean. After I ran the command though...I can't get in on either port 22 or 5555.

The connection times out. Have I locked myself out now somehow?

Do you have a firewall already setup? Unless you put that line in the startup script it won't be reapplied on reboot so that could get you back in.
Does your employer block port 5555 as well? I can test it if needed if you want to post or PM me the ip.

Not yet...I was going to wait until I had time to read up on APF a bit first (or hire Acunett to do it for me).

I just rebooted it for now...I forgot that I have access to one of our DMZs so this isn't as big an issue as I thought originally

I appreciate the help...and the quick replies Sean