[c-nsp] Using MPLS PEs as gateways for access layer

[Phil Mayers]

On 30/11/2016 11:23, Ryan L wrote:
> Thanks guys, this is good information.
>
> I will be using some 6500s with Sup720 - for the time being - on this
> particular application.
>
> Just to make sure I've properly articulated, the PE routers at each site
> are my only layer 3 termination point, and would also be doing transit
> routing between locations via iBGP over my IGP as well (so technically P
> router duties as well?) -- more or less every job except for the access
> aggregation, which would go ToR.

Yes. Our previous topology was only 2-deep:

PExN -(layer 3 ospf/ibgp/ldp)- 6500/sup720 PE -(layer2)- edge switch

...with the 6500 being a P/PE, and terminating first-hop routing for 
thousands of hosts in vlans on the edge switches, into SVIs inside 
L3VPN. As noted, subject to some caveats about aggregate labels & 
recirculation on that platform, we had no issues, it has been very solid 
for many years.

There are more layers involved now, but we still have the L2/L3 boundary 
on a P/PE, and it still works.