Fixing SSH -L Connection: Localhost Port Forwarding Failed on macOS

If you are encountering an issue with SSH -L connection, specifically a "localhost port forwarding failed" error on macOS, don't worry, there are a few steps you can take to resolve this issue.

First, make sure that the SSH command is properly formatted with the correct syntax. The -L option is used for local port forwarding, and the syntax should be as follows:

ssh -L [local_address:]local_port:remote_address:remote_port user@server_address

If the syntax is correct and you are still encountering issues, try specifying the local address as "127.0.0.1" instead of "localhost". This can sometimes resolve the issue.

If neither of these solutions work, it may be a firewall issue. Check to make sure that your firewall settings are allowing SSH connections and port forwarding.

Finally, if all else fails, try restarting your SSH service or rebooting your computer to see if that resolves the issue.

In summary, to fix the SSH -L connection "localhost port forwarding failed" error on macOS, make sure your command is properly formatted, try specifying the local address as "127.0.0.1", check your firewall settings, and restart your SSH service or computer if necessary.