I am attempting to VNC access a server through a RaspPi B+ running Raspbian. I can access the server fine using ssh; however, the pi unit seems to have port 5901 and 5902 blocked.

I am VPN'd into the server using openvpn. I am not sure if this makes any difference.

The results of the netstat -natp command result in the port 5901 having a status of "sync sent". I have seen similar instances when a firewall is blocking a port from sending data out, but I do not have iptables active. I actually installed ufw and allowed out port 5901 to see if that helps, which it doesn't.

A linux laptop and an Android cellphone have no troubles connecting to this server. The laptop uses xvncviewer; this is what I am attempting to use on the pi unit.

Any ideas?

  • As the RaspPi is the VNC client, it is most likely that the ports are blocked on the VNC server or on a router on the way. – RalfFriedl Feb 20 at 6:07
  • I agree; however, the laptop is running on the same network and connects without any issues. It is as if the pi is blocking the ports itself. – branch.lizard Feb 21 at 2:06
  • Run tcpdump on the PI and watch the output if iptables -vnL.. – RalfFriedl Feb 21 at 17:40

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