Copy/pasting from the e-mail I just sent you: """ It's a reserved prefix by Xen for use by hypervisors and has been used by a fair number of other hypervisors and container projects who didn't get their own allocation.
So I remember someone looking into using a different prefix in the past, including looking into local addresses, from what I remember the issues with them were: - Bad rendering in dump tools as there is no OUI assignement for them - Has a very high probability of being a higher number than a physical MAC, which is a problem since on Linux bridges use the highest MAC as their own and a change of MAC can stop forwarding for a few seconds. This limitation went somewhat away with recent kernels where we can now force the MAC regardless of slave ports. - Some broken switches, at least back then (a few years ago) were interpreting the local bit as meaning, switch-local and so weren't forwarding packets coming from such a MAC (similar to if those were STP frames). My personal preference was for us to register a new prefix for use by LXC containers and switch from the Xen to our own prefix everywhere in LXC and LXD. This would avoid the problems above and after the various OUI databases get updated, show very clearly what those MACs are in the various network reporting tools. I unfortunately didn't get much traction on getting that paperwork done (and fee paid) so we've been sticking with the Xen range for now. """ -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1660542 Title: container mac addresses should use 'locally assigned' section To manage notifications about this bug go to: https://bugs.launchpad.net/juju-core/+bug/1660542/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
