16.04 and 17.04 in Hyper-V does not resolve names on the network

I am using vagrant for the development and recently had to switch from VirtualBox to Hyper-V due to the requirement of developing for docker in windows. I have modified my vagrant files to use hyper-v as provider which require me to switch image from ubuntu/xenial64 to generic/ubuntu1604. I've configured the boxes to use the Hyper-V Switch that is configured as external for networking. When I am getting my VM up it cannot resolve any network names (though it resolves google or any other internet name fine). I thought it might be due to Hyper-V but Knoppix liveDVD with the same settings can resolve local network names fine. I tried 17.04 and having the same issue as in 16.04. What could be tweaked in the network configuration to get that working?

update: Ok. Looks like the issue in /etc/resolv.conf. By adding

nameserver 192.168.1.2 # my local dns

I am able to get to the hosts. However looks like when I reboot the VM this file is getting reset and I need to add local manually. What is the service that is doing such things on Ubuntu?

1 Answer

Ok. After little bit more digging I found out that /etc/resolv.conf is maintained by resolvconf service and by editing files under /etc/resolvconf/resolv.conf.d/ I would be able to permanently add information to /etc/resolv.conf

By end of the day I've endup modifying /etc/resolvconf/resolv.conf.d/head by adding my local dns as the 1st entry and restarting networking service.