Comment 135 for bug 1754671

No, ipv4.dns-priority=-1 breaks older NM because there, there's no default routing domain ~. and not even any way to set it. So lookups outside the VPN domains are just refused instead of being leaked to the local nameservers as they were before.

As it happens, we configure our DHCP client to always override the discovered search domains to our corporate AD domain dom.company.com, so I can work around NM's failure to automatically set ipv4.dns-priority=-1 a different way — by manually configuring the VPN with ipv4.dns-domains=dom.company.com;company.com;. That works for both old and new NetworkManager.