Comment 20 for bug 393094

I just read the syslog excerpt above.

I recently had a similar issue in 15.10 and want to share my experience:

The symptoms: Timeouts and connection termination after some minutes. I used openconnect vpn connector.

After several experiments I figured the source of the problem being that my home network is a class A network (10.x.x.x) and the destination network is a class A network (10.x.x.x) as well.

Keep alive packets follow the routing table and in my case, this included the default route pointing to my router.
The router tunnels the vpn connection but does not route it which means that keep alives will not reach the remote endpoint and the connection runs into timeouts.

I found no solution to this issue other than using an alternative network connection (using mobile modem which issues a different home IP address 172.16.x.x). Now the connection is stable and keep alives are forwarded correctly.

Note: Even static routes do not help as the endpoint of the vpn tunnel has rolling IP addresses.

Why do I believe there is a connection?

see:
Jun 28 11:30:06 xb pppd[3306]: Cannot determine ethernet address for proxy ARP
Jun 28 11:30:06 xb pppd[3306]: local IP address 10.113.214.1 <========================
Jun 28 11:30:06 xb pppd[3306]: remote IP address 10.64.64.64 <========================

I hope this helps