From: David Wragg <david@weave.works> Date: Wed, 6 Jan 2016 13:33:04 +0000
> Prior to 4.3, openvswitch vxlan vports could transmit vxlan packets of > any size, constrained only by the ability to transmit the resulting > UDP packets. 4.3 introduced vxlan netdevs corresponding to vxlan > vports. These netdevs have an MTU, which limits the size of a packet > that can be successfully vxlan-encapsulated. The default value for > this MTU is 1500, which is awkwardly small, and leads to a conspicuous > change in behaviour for userspace. > > These two patches set the MTU on openvswitch-crated vxlan devices to > be 65465 (the maximum IP packet size minus the vxlan-on-IPv6 > overhead), effectively restoring the behaviour prior to 4.3. In order > to accomplish this, the first patch removes the MTU constraint of 1500 > for vxlan netdevs without an underlying device. Is this really the right thing to do? Won't we get a lot of fragmentation by using such a large MTU, especially since you're making it the default for OVS setups? Things like path MTU discovery hinge strongly upon accurate MTU settings. Otherwise they won't function properly. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
