[Rdo-list] R: R: Jumbo MTU to instances in Kilo?

[Erich Weiler]

> Lastly, has anyone ever run into problems when running (MTU - 50 bytes)
> as the veth_mtu with VXLAN? I see documentation all over recommending
> (MTU - 100 bytes), but I don't see why VXLAN should take that many
> extra bytes. I've done extensive testing at VM MTU 8950 over a 9000 MTU
> link, and never run into an issue. Is this just cargo-culting, or is
> there a reason to give VXLAN additional headroom in some scenarios?

Along those same lines...  I'm running tenant segregation via regular 
VLAN segregation (not VXLAN or GRE), using all interfaces set to 
MTU=9000 (the instance all the way up to the main network gateway, all 
router interfaces, etc).  My physical switches have MTU=9260 on all 
ports however.

It seems to work and perform OK, but is there a recommendation on giving 
regular VLANs a little VLAN-tag headroom as well?  Like, should I be 
setting my instance MTU to 8950 or something?