MTU breakage in f20

[Tom Horsley]

On Mon, 03 Nov 2014 08:25:32 +0800
Ed Greshko wrote:

> So, no trouble here.

I've had some trouble, but only in very odd circumstances:

I have a f20 machine hosting a slew of virtual machines on
a bridge network with the virtual machines on their own separate
subnet on one bridge and the f20 machine serving as a router.

Some of the virtual machines (I detected no pattern, I've got
lots of different vintage linux distros in the VMs) could not
successfully talk NFS to old servers that use UDP. This seemed
to have something to do with MTU and routing UDP packets. Wireshark
would show errors about UDP packets that needed to be split,
then show different errors about being unable to split them.

I forget exactly how I fixed it - I think it was by installing
a newer kernel than the one that came with f20 at the time
I first installed the host.