Automatic name resolution within an Ubuntu 14.04 container?

When I set up an Ubuntu 14.04 container running under Ubuntu 16.04, name resolution from within the container works automatically. If however I follow the same steps to set up an Ubuntu 14.04 container running under Arch Linux (installed from lxd AUR package), name resolution does not automatically work from within the container. In both cases, /etc/resolv.conf contains the IP address of lxdbr0.

There is an easy fix, of course; I just add my local name server to /etc/resolvconf/resolv.conf.d/base and run resolvconf -u, but I’m trying to understand how all this works, so am not sure what the difference is. By default, the Ubuntu 16.04 default is USE_LXD_BRIDGE=“true”, while the default in Arch Linux is USE_LXD_BRIDGE=“false”, but I changed this to true, restarted lxd and built another Ubuntu 14.04 container under Arch with the same outcome. And come to think of it, it’s not clear why the resolv.conf IP address in the first Ubuntu 14.04 container instance under Arch is set to lxdbr0, given that the default was set to not use lxdbr0. I can’t find any other relevant configuration option.