Error: "channel 3: open failed: administratively prohibited: open failed" on OS X Screen Sharing over ssh tunnel

Question

I had configured OS X screen sharing over an ssh tunnel and at some point it stopped working. The ssh tunnel would work:

ssh -L 1202:localhost:5900 user@remote-host.com

However, when attempting to make the screen sharing connection ( vnc://localhost:1202 ), the remote host would error with

channel 3: open failed: administratively prohibited: open failed

Answer 1

I have the following in my remote host's ~/.ssh.config :

AllowTCPForwarding yes
PermitOpen any

The missing element was an entry in the remote host's /etc/hosts that defined localhost . I added the following to that file and screen sharing over ssh tunnel was restored:

127.0.0.1 localhost