If you are not already running MPLS, then I would rule VPLS out... though there are some benefits to biting the bullet and learning MPLS and virtualizing your network with it. L2TPv3 is a better option than GRE, in my opinion. Also having dark fiber means large MTUs yes? I think that would be preferable...
--- On Wed, 7/6/11, Jason Gurtz <[email protected]> wrote: From: Jason Gurtz <[email protected]> Subject: [c-nsp] GRE tunnel to do span vlan across two datacenters? To: [email protected] Date: Wednesday, July 6, 2011, 11:08 AM A firm has proposed creating a GRE tunnel between two datacenters (using a 3750X stack at each) to create the spanned vlans needed for VMWare failover application. Clearly there is tunnel overhead but I sense there are other failure modes here that aren't so clear to me--I am familiar in concept with GRE tunnels but don't have a heck of a lot of opex. Can anyone share more insight on the merit (or lack of) with this proposed design? I am aware (via this list, thanks!) of several shortcomings surrounding 3750 based stacks, but cisco alternatives seem pricier still or too big. There is dark fiber available, what about VPLS w/ LDP or L2TP solution? Current network is L3 at the access layer w/ OSPF (4507-sup6 access, 4900M cores): A1 /\ / \ C1------C2 \ / \/ A2 Maybe it is better to just overlay stp back on to the network w/root and alt-root at C1/C2 (V1 and V2 are the proposed 3750X stacks)? Scary to me, but an an argument can be made for less complexity -vs.- tunnling/vpn based approach. A1 .V1 /\ . ' / /. ' \ / C1------C2 \` . / \ \/ ' . \ A2 'V2 OTOH, by the time this actually gets done maybe TRILL will be out ;) Hopefully this enterprisy topic is not too OT! ~JasonG _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
