>From talking to our Cisco SE, the initial release of OTV will likely on support a low-ish number of VLANs, with the likelihood that the number will increase over time as additional testing is performed. A back-to-back vPC between pairs of Nexus make work between two DCs, but separate physical links for L3 interconnects may be an issue. Given this may scale to more than two DCs, solutions such as VPLS/A-VPLS begin to look attractive.
BTW, is is permissible to use a vPC peer link between two Nexus for non-vPC traffic; thinking in the scenario where the access layer design comprises of squares rather than triangles. Cheers, Matt On 22 July 2010 13:13, Lincoln Dale <[email protected]> wrote: > On 22/07/2010, at 8:16 PM, Matthew Melbourne wrote: > >> Is it possible to extend two vDCs between Data Centres using OTV (pair >> of N7k on each site) - it's not clear how OTV uses vDCs to extend the >> L2 domain. > > yes, its possible. there are 3 methods: > > 1. OTV runs inside a Virtual Device Context. for 2 VDCs you could run OTV in > each of them. > this approach requires 'WAN' connectivity to each VDC - perhaps a downside > if its not already there. > > 2. if you don't have overlapping VLANs between the VDCs then you can trunk > the VLANs (L2) from one VDC to another using a crossover external cable (1G > or 10G or Nx1G/10G depending on your traffic levels), then use a single OTV > instance to transport all the VLANs between sites. > > 3. you could run a single instance of OTV within each VDC (similar to #1) > with the 'WAN' IP connectivity to the OTV cloud achieved via a single VDC > with a crossover external cable (1G or 10G, doesn't really matter) @ L3 > between VDCs to the single VDC that has WAN connectivity (similar to #2). > i.e. sort of a hybrid of the above two. > >> Also, is it correct that Unicast-only transport support (and hence the >> use of an Adjacency Server) is not supported initially (looking at the >> BRKDCT-2049 Networkers' presentation). > > correct. > > >> >> Alternatively, are there other mechanisms to achieve L2 connectivity >> for two separte L2 domains over a pair of redundant links between Data >> Centres? > > quite a few ways of doing it, but OTV does solve some unique problems and > issues with the various other approaches. > > > cheers, > > lincoln. -- Matthew Melbourne _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
