Layer2 over Layer3

David Swafford david at
Thu Sep 13 02:46:28 UTC 2012

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:  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.


On Wed, Sep 12, 2012 at 3:37 PM, Paul Vinciguerra
<pvinci at> 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:source_route at]
> 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

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