Sharing SSH Tunnels Across a Local Network

Run below command on machine A. It starts a SOCKS server listening on the port 8080, and forwards all traffic to that SOCKS server to the remote host, over the secure channel.

  # ssh -C -D :8080 -N <username>@<remote-host>
  ssh -C -D :8080 -N test_user@1.2.3.4

Note the value of the -D option, :8080, which is prefixed with a :. -D :8080 means the listening port is bound to all interfaces of machine A, not just to localhost.

Other machines in the same local network now can access that SOCKS proxy using the IP address of machine A.

Also configure the network settings on machine A to use a fixed IP address, so that other machines don’t have to update the SOCKS proxy IP often. (Choose “Using DHCP with manual address” in MacOS Network settings.)

This is a workaround to fix the broken SSH tunneling after I upgraded my Mac to MacOS 15.0 Sequoia.