Re: [PATCH net] gso: do GSO for local skb with size bigger than MTU
From: Michael S. Tsirkin <hidden>
Date: 2014-12-04 10:17:07
On Wed, Dec 03, 2014 at 10:56:02AM -0800, Rick Jones wrote:
Trying to "fake-out" an ICMP message to paper-over "devices" in the "middle" of same Layer2 network having different MTUs from the ends goes back to at least the days when people started joining FDDI networks to Ethernet networks with bridges rather than routers. Perhaps back even further. It had problems them (including not all traffic being IP), I doubt today would be any different. All devices in a Layer2 network must have the same MTU. (*) The only exception to that which does not lead one down a rathole is that you can have the MTU at the "edges" of the Layer 2 network be smaller than the MTU in the "middle." And then only if the middle "never" tries to talk itself to the edges directly. rick jones (*) Or at least any communicating device must be kept ignorant of what one does to have a smaller MTU in there somewhere.
What I've been pointing out is that just because something is within a VM, we can't assume it's an edge. -- MST _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev