On 05.08.2015 03:30 PM, Will Smith wrote:
Dear All,
I'm having a stange problem when attemping to connect to my Centos server using x2goclients (Ubuntu & mac, 4.0.5.0). I'm running firewalld, but port 22 is unblocked and I am able to ssh into the machine and forward X traffic. When accessing from both a mac and an ubuntu client the session appears to start, but then immediately disconnects. The client logs say:
Info: Proxy running in client mode with pid '12054'. Session: Starting session at 'Wed Aug 5 12:38:47 2015'. Info: Using abstract X11 socket in kernel namespace for accessing DISPLAY=:0. Info: Connecting to remote host 'localhost:31003'. Info: Connection to remote proxy 'localhost:31003' established. Error: The remote NX proxy closed the connection. Error: Failure negotiating the session in stage '7'. Error: Wrong version or invalid session authentication cookie. Session: Terminating session at 'Wed Aug 5 12:38:53 2015'. Session: Session terminated at 'Wed Aug 5 12:38:53 2015'.
If I attempt to reconnect, I can see the session, but am unable to resume it. The strange thing is that if I stop firewalld, I'm able to access the server from both clients with no issues, which implies it's a firewall issue, but as I say port 22 is unblocked and I can forward X traffic. Is there some other obvious firewall setting I've failed do? Any assistance in fixing or diagnosing this issue would be highly appreciated.
X2Go makes extensive use of SSH tunnels. I suspect your firewall is too strict and denies access from localhost to localhost. Please make sure that locally, all connections are allowed.
Mihai