SSH Reverse Port Forward Bind to address

sshssh-tunnel

So, I have a script setup to automatically open a SSH connection to my server, and reverse port forward a port to me for SSH connections to my home desktop. This script has always worked until now that I've migrated servers.

The short of it is that I can't get this connection to bind on the external IP address, and I'm not sure why.

The script basically runs this command (I can confirm that this command with my values subbed in has the same result when run from a shell):

sudo autossh -M 5114 -D 7474 -R servers_public_ip:2695:localhost:22 -i /home/user/.ssh/id_rsa2 remote@servers_public_ip

When I check lsof, I see the following connections bound for the remote user:

sshd      27570   remote    3u  IPv4 161761      0t0  TCP servers_public_ip:22->67-213-103-227.eastlink.ca:62812 (ESTABLISHED)
sshd      27570   remote    7u  IPv6 161773      0t0  TCP ip6-localhost:5114 (LISTEN)
sshd      27570   remote    8u  IPv4 161774      0t0  TCP localhost:5114 (LISTEN)
sshd      27570   remote    9u  IPv6 161777      0t0  TCP ip6-localhost:2695 (LISTEN)
sshd      27570   remote   10u  IPv4 161778      0t0  TCP localhost:2695 (LISTEN)

None of these bindings are on the servers public ip, save for my ssh connection to the server to run lsof. This worked fine on my old server. I've checked sshd_config and turned on AllowTcpForwarding explicitly. I'm running out of ideas.

Best Answer

I hate when this happens, but after a little more research, I'm able to answer my own question.

It seems that sshd_config needed to have GatewayPorts yes to bind to external addresses. I must have missed this when porting over the configurations.

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