How to find the IP of the source of an SSH reverse tunnel?

Using lsof -i I can see there is a reverse ssh tunnel set up on my server:

sshd       1321   remote    8u  IPv4 219299       TCP localhost.localdomain:mvs-capacity (LISTEN)

How can I find out the IP address of the machine that created this tunnel?

Thanks

Solution 1:

lsof -nPp 1321

Run lsof -i | grep 1321 to see the other connections the pid has, one of which should be the ip of the machine that created the tunnel.