How to fix request failed on channel 0

Question

When I want to connect to my server like this

ssh -a username@my-server.de -p 22

it gives me two error messages:

PTY alloca         


        

Answer 1

I solved a similar problem with one of our users who was used only for ssh port forwarding so he don't need to have access to PTY and it was prohibited in .ssh/authorized_keys file:

no-pty ssh-rsa AAA...nUB9 someuser

So when you tried to log in to this user, only message

PTY allocation request failed on channel 0

was returned. So check your user's authorized_keys file.