Giles,
> > Of course one may say that I can use L3VPN or L2VPN no need for > something in the middle - fair point. But in the same time this is > different from prohibiting one to inject some host routes and do proxy arp > for pair of VMs which like to talk on the same subnet but happen to be > sitting on different compute nodes. > > but as you yourself have said - if there's no need for it then why add it? > There are many different ways those two VMs can communicate already. I'm > not sure we need to invent another > And that is reasonable discussion to have here rather then argue that BGP does not scale without providing pain points or that routers behind VM need to talk L2 to other routers behind VM (the latter is in fact possible via overlay over overlay today anyway if someone would desire so). You may be of opinion that current EVPN or PBB EVPN solve the problem. I agree they solve the problem, but the price is much higher - new development and new protocol extensions are needed to support it. Operating one more protocol is not free too. Here we just have a informational draft illustrating much cheaper option to allow hosts talk on the same subnet cross overlay boundary. I do see this as interesting tool to some of VMs communication requirements. > > And while some vendors do fight hard against overlays for tenant > virtualization and would rather see all smartness of the networks in TOR I > am afraid that this ship has already left the harbor .... In the above VMs > are virtualized in the compute's node kernel eliminating any need for big > fat and expensive PEs acting as TOR. > > thanks for putting words in my mouth Robert. I appreciate it ;) > You are more then welcome ;-) r.
