NM forces IPv6 default route via VPN and ignores ipv6 settings
When activating an OpenVPN connection using NetworkManager my system ends up routing all IPv6 traffic trough the VPN, despite the given NM connection options:
-
ipv6.method
being set todisabled
-
ipv6.never-default
being set toyes
-
ipv6.ignore-auto-routes
being set toyes
Current workaround is to establish the connection and then either remove the route manually:
# Note: Doesn't work
# Something (NM?) is just re-adding the route after removal
sudo ip -6 route del default dev tap0
Or disable IPv6 for this particular interface:
echo 1 > /proc/sys/net/ipv6/conf/tap0/disable_ipv6
I'm running the default NetworkManager setup on a Ubuntu 20.04 desktop.