LXD Container in 16.04: APT forces IPv6?

I installed a new 16.04 server and spun out a couple of 16.04 containers with LXD. The host server works fine with APT getting IPv4 addresses from DNS. Both containers are getting back IPv6 addresses. I've got a bridge set up on the host and set that bridge to be the default bridge for containers, so both containers are getting DHCP from the same source as the host. No idea what is going on here.

This is what a vanilla container shows:
Err:1 http://archive.ubuntu.com/ubuntu xenial InRelease
Could not coect to fe80::1%eth0:13128 (fe80::1%eth0), coection timed out

I've tried disabling IPv6:
net.ipv6.conf.all.disable_ipv6 = 1
net.ipv6.conf.default.disable_ipv6 = 1
net.ipv6.conf.lo.disable_ipv6 = 1

But all that does is get me address family not supported errors:
Err:3 http://archive.ubuntu.com/ubuntu xenial Release
Something wicked happened resolving 'fe80::1%eth0:13128' (-9 - Address family for hostname not supported)

Oddly the container interfaces on the host show as having an ipv6 address and no ipv4:
vethSQ3Y4C Link encap:Etheet HWaddr fe:ba:78:7c:e6:a0
inet6 addr: fe80::fcba:78ff:fe7c:e6a0/64 Scope:Link

Yet lxc list clearly shows it has having an IPv4 address and no IPv6:
NAME | STATE | IPV4 | IPV6 | TYPE | SNAPSHOTS |
+---------+---------+-----------------------+------+------------+-----------+
| bastion | RUNNING | 10.255.251.167 (eth0) | | PERSISTENT | 0 |

The interface in the container shows both ipv4 and 6:
eth0 Link encap:Etheet HWaddr 00:16:3e:45:bb:d9
inet addr:10.255.248.86 Bcast:10.255.251.255 Mask:255.255.252.0
inet6 addr: fe80::216:3eff:fe45:bbd9/64 Scope:Link