Comment 6 for bug 1656326

Ah... do the interfaces names on the host span close to 15 characters? I noticed this in the logs "qbr420ddec0-7a". When juju creates the bridges for the container it add a prefix of 'br-' which will take the names to >15 characters; 15+NULL is a hard limitation in the kernel and I suspect the bridge does not get activated and, due to a different Juju bug[1], we fall back to using lxdbr0.

[1] - the bug in question in similar to https://bugs.launchpad.net/juju/+bug/1656217 - the code path currently ignores errors when it should return with an error. By ignoring the error we default to using lxdbr0.