If the command line or NetworkManager.conf mentions a non-existent
domain, just print a warning and ignore it. That way if you switch to
using an older NM that doesn't have that domain, it will still work.
ndp_open() can fail, do not assume it cannot.
When 'ipv6.disable=1' kernel parameter is used, the whole IPv6 stack is
disabled and the attempt to create PF_INET6 socket fails.
https://bugzilla.redhat.com/show_bug.cgi?id=1012151
Abstract class, fake implementation and a manual testing tool for
NetworkManager's internal IPv6 router discovery module. When a real
implementation is ready, it will replace nm-ip6-manager and will be used
by nm-device.
