Comment 5 for bug 1944083

The configuration can be replicated via the shell using `route add <NS-IP> gw <DEF-GW-IP>` for every DNS server specified.
I'm seeing the same behavior go back to Mitaka at least, possibly even liberty.
Our clouds have an OutsidePublic net - real WAN, and OutsidePrivate net - an "external network" inside the datacenter (shared by all 3 openstacks in there). The GW to OutsidePublic is set to be the default, but the DNS servers (a designate set in the Wallaby cloud) are on the OutsidePrivate segment. Adding explicit routes to using the OutsidePrivate GW fails because _something_ is setting explicit routes to each NS/32 via the default GW which overrides the routes being set for the VPC network needing to get DNS resolution.