Philip, Here is the best reference I know of to address your issue.
http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/white_paper_c11_493718.html#wp9000281 From: Philip Lavine [mailto:[email protected]] Sent: Friday, September 14, 2012 6:06 PM To: David Swafford; Paul Vinciguerra Cc: NANOG list Subject: Re: Layer2 over Layer3 If the psuedowire is setup to allow a vlan to be exteneded, but the vlan is already extended over a dedicated link, how will spanning tree behave? Right now I have it setup and I dont see the psuedowire trunk in a blocking state. Will the switch that has both the pseudowire trunk on it and the dedicated link know how to forward the frames if either goes away? From: David Swafford <[email protected]<mailto:[email protected]>> To: Paul Vinciguerra <[email protected]<mailto:[email protected]>> Cc: Philip Lavine <[email protected]<mailto:[email protected]>>; NANOG list <[email protected]<mailto:[email protected]>> Sent: Wednesday, September 12, 2012 7:46 PM Subject: Re: Layer2 over Layer3 Hey Philip, Any Transport over MPLS will do this too. Here's a link to an example setup of two sites where just L3 connectivity exists between them: https://w.ntwk.cc/working-on-atompls/. In that setup, I have just IPSEC VPN connecting the two locations, but have an 802.1q trunk extended between both. In the example configs, Fa0/1 on both ends is a transparent L2 connection. The boxes used here were 3725s on 12.4T. David. On Wed, Sep 12, 2012 at 3:37 PM, Paul Vinciguerra <[email protected]<mailto:[email protected]>> wrote: > ASR supports OTV if you can do multicast over L3. Although, you may not need > L2 extensions in the end. > > -----Original Message----- > From: Philip Lavine > [mailto:[email protected]<mailto:[email protected]>] > Sent: Wednesday, September 12, 2012 6:23 PM > To: NANOG list > Subject: Layer2 over Layer3 > > To all, > > I am trying to extend a layer2 connection over Layer 3 so I can have > redundant Layer connectivity between my HQ and colo site. The reason I need > this is so I can give the "appeareance" that there is one gateway and that > both data centers can share the same Layer3 subnet (which I am announcing via > BGP to 2 different vendors). > > I have 2 ASR's. Will EoMPLS work or is there another option? > > Philip >
