On Ubuntu 14.10, I'm connecting to the same VPN service using either OpenConnect (through the
network-manager-openconnect(-gnome) packages or the Cisco AnyConnect Client. Using the AnyConnect client, I have had no problems, while OpenConnect gives me strange connection issues (but only with some programs).
I suspect the problems are caused by the fact that the VPN provider does not support IPv6. Connecting to http://whatismyipv6.com using the AnyConnect client, an IPv4 address is displayed, while using OpenConnect, my (non-VPN!) IPv6 address is shown. The AnyConnect client seems to force all connections through the VPN, even if IPv6 is unavailable. The following is a screenshot of the Statistics -> Details page in the AnyConnect client:
How can I achieve the same using OpenConnect? In Network Manager, under "Edit connection", there is an "IPv6 settings" tab, but the only relevant setting seems to be "Method" with the options "Ignore", "Automatic (VPN)" and "Automatic (VPN) addresses only" – I don't know what the difference between them is, but none of them seem to do what I want. Is the
--disable-ipv6 flag that can be given to
openconnect related? How would one use that in Network Manager?
Note: I have seen this question about disabling IPv6 with OpenVPN, but the answer given there is unsatisfactory – I don't want to manually and globally enable/disable IPv6 every time I connect to or disconnect from the VPN.