On Tue, 23 Feb 2016 09:00:56 +0800 roy.qing...@gmail.com wrote: > This is especially annoying for the virtualization case because the > KVM's tap driver will by default adopt the bridge's MTU on startup > making it impossible (without the workaround) to use a large MTU on the > guest VMs. > > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1399064
This use case looks like KVM misusing bridge MTU. I.e it should set TAP MTU to what it wants then enslave it, not vice versa.
