OpenVPN Support Forum

Hello!
I setup an OpenVPN server on my Raspberry Pi at my place and installed the client software on my Android phone.
I can connect to my server just fine both if my phone is connected to my home wifi [same network as the RPi] and also if my phone is connected to mobile data when I'm away from home.

Surprisingly -- for me at least! -- OpenVPN fails to connect when my phone is connected to my university wifi, be it eduroam or the institute's own network. I always get a server poll timeout. As soon as I disconnect from the wifi and connect to mobile data again, OpenVPN reconnects instantly.

I talked to the institute's sysadmin and he suggests it might be because the local firewall blocks most outbound connections and that he will try to open port UDP 1194 [which is the one I am actually using].

Is there anything else that could be causing this problem?

Thanks in advance for any help!

The list of possible problems is practically endless.

Ok... Where do I start then?

Hi m,

"Server poll timeout" always means that there was no reply received from the server. The client thinks it sent its initial packet to the server, but if it did, there was no reply.

Talk to your university help desk. My guess is that they are not allowing Internet access, merely some sort of proxy service. They're not allowing any UDP packets out.

Often you can get through such proxies when using Access Server, because it implements daemons on each of TCP/443 and UDP/1194. The TCP packets usually get through.

You can also try a tcpdump(8) on your VPN server to see if any packets are received. Again, I bet they are not.

regards, rob0

Hello Rob0,

thanks for your reply! First of all, I'm happy to report that after my institute's sysadmin allowed outgoing connections to port UDP 1194 I can now connect fine to my remote server from the local wifi, so the issue is solved.

That being said, I now have a conceptual question: it seems like any VPN-averse network can easily prevent all users from using VPNs by just blocking port UDP 1194. Is this a fundamental limitation of VPNs?