cyclical connect/disconnect over cellular

[kevincw01]

I recently started using openvpn connect to log into my openvpn server from my phone over verizon wireless LTE. The app connects and I get about 10 seconds of connectivity to my internal network before it stops working. In the log of openvpn connect app, I see "udp send error: send: Invalid argument" when this happens. At the same time, my phone reports that it is disconnected from the tower data connectivity (4G symbol changes from light to dark grey). The LTE data connection comes back about 10 seconds later. Openvpn connect will see that data service is back and re-connect successfully and the cycle continues. This loss of data connectivity _only_ happens when I try to use openvpn and is consistently repeatable so it's clearly correlated. I am configured for UDP and port 1194 on the server.

Any ideas how to correct this issue? Also, I'd like to post the openvpn log file but I can't find it on the phone, where is it?

[kevincw01]

I found the client config that I imported into the open vpn connect app on my phone and have pasted it below.

Code: Select all

dev tun
persist-tun
persist-key
cipher AES-256-CBC
auth SHA256
tls-client
client
resolv-retry infinite
remote <mydomain> 1194 udp
lport 0
verify-x509-name "openvpn" name
auth-user-pass
pkcs12 fw1-udp-1194-openvpn.p12
tls-auth fw1-udp-1194-openvpn-tls.key 1
ns-cert-type server
comp-lzo adaptive

[kevincw01]

bummer, no tips here?

[TinCanTech]

Can you connect with a standard PC ?

[kevincw01]

yes and via phone when using wifi.

[TinCanTech]

At the same time, my phone reports that it is disconnected from the tower data connectivity (4G symbol changes from light to dark grey). The LTE data connection comes back about 10 seconds later. Openvpn connect will see that data service is back and re-connect successfully and the cycle continues

I would think that is the problem. Have you contacted your service provider for help ?

Alternatively, you could try a TCP VPN for testing purposes.

[kevincw01]

agree, however I was hoping there was a known attribute of my VPN config that Cellular networks don't like that could be tuned to prevent it. I have not called Verizon yet as it seems daunting. I'll try tcp today and report back.

[kevincw01]

TCP has the same problem. I disabled an option on the openvpn server (pfsense) called "Force all client generated traffic through the tunnel" which keeps the connection up greater than 10 seconds. I even though I had success because I was able to continuously ping devices on the LAN and browse external websites without being disconnected from the verizon network. However if I navigate to an internal website, the 4G data connection is instantly dropped.

[TinCanTech]

I would advise you to contact your service provider.