I am building an MCSA lab in Hyper-V on my Windows 8.1 PC. I have 2 physical NICs on the PC with 1 NIC for Hyper-V and the other for the host PC LAN/Internet traffic. Physical network is 192.168.0.0 with gateway 0.254. Two virtual NICs were created on my host PC with the v-switches and I renamed them to "vEthernet (LAN 10)" and "vEthernet (LAN 20)".
In Hyper-V I have an external v-switch ("Hyper-V External") connected to the dedicated Hyper-V NIC and two internal v-switches ("LAN 10" and "LAN 20"), all are being used with a virtual VyOS router for 2 separate LANs and a route to the physical network. This all works as desired:
On LAN 10 I have a domain controller ("DC1") at 10.100 that is running DNS and DHCP. When I enabled DHCP, "vEthernet (LAN10)" on my host PC pulled DHCP with a 10.254 gateway and a 10.100 DNS as I would expect but I noticed that when I shutdown DC1 I could no longer get to the Internet on my host until I disabled "LAN 10".
Doing a tracert from my host I found that traffic is being routed to the "LAN 10" gateway on the VyOS router first (10.254) and then to the physical router (0.254) and route print shows a route with gateway 10.254 with a metric of only 5 so that all traffic from my host is being routed through the virtual "LAN 10" interface rather than the physical "Ethernet" interface. I can delete the route to 10.254 and my first hop then becomes the physical router at 0.254 but if I disable and re-enable "LAN 10" the route to 10.254 with metric 5 comes back. Additionally, nslookup on my host defaults to 10.100 ("DC1"). If I disable "LAN 10" it will then default back to the DNS I statically assigned to my "Ethernet" NIC.
For now I'm just leaving the "LAN 10" interface disabled which doesn't affect VM network communication at all, it just keeps LAN 10 off my physical PC. I couldn't ping or RDP into VMs on that network from my host until I added a static route on my physical router to the VyOS router. This works but I don't get DNS resolution from anything on that network.
Should I just leave LAN 10 disabled or is there something I've overlooked that I need to (re)configure? I tried to change the metric of the default route to 0.254 from "266" to "4" but it will not go lower than 14. I would also like to know why it behaves this way - why are the virtual NIC settings given priority over the physical NIC settings? Is a NIC pointing to a domain given precedence over a NIC on a workgroup?
Thanks!
zp.