6500 Virtual Switching System (VSS) design in MPLS PE PoP

[siddiqirf]

I have a design question regarding a Service provider style MPLS PoP with dual 6500 PE Routers.

Each MPLS PoP currently is running two PE routers for resiliency.The CE routers dual home to each MPLS PE router at Layer 3 into the MPLS VPN/vrf. The traffic is load balanced in/out for different VRF's based on HSRP and routing preferences. 

My question is what is the benefit or pros and cons of running Virual Switchi system (VSS) on the two 6500  PE routers and treating the two as One logical PE router.

I can understand the benefit of VSS with Multichassis Etherchannel (MEC) in a Data center or access layer type setup, but not sure if it is recommended or beneficial to run VSS on a Service provider MPLS setup for PoP node resiliency

With the current setup I can manipulate the traffic based on routing preferences and have more control. But with VSS since the device is acting as one PE router, will i have the same ability to control traffic patterns?

My other concern is that on the dual homed CE routers, the PE-CE BGP routes will appear coming from one PE whilst in VSS, same BGP neighbour. This may be harder to troubleshoot issues.

Please advise..

Regards

Irfan S.

[Michael Kiessling]

Hi,

From my point of view I agree on what you say. I don't think that a VSS system has any advantage in a SP environment like the one you described. The best place for VSS is in a layer 2 enterprise network or datacenter.

Regards,

Michael

[JohnTylerPearce]

Well, if you setup a VSS, and instead of two PEs you know had one, I could see the manageability side of this configuration being better. But at the same time, you will logically only have one PE, instead of the two PEs you had earlier. I'm assuming you could run a L3 port-channel from the CE to the PE. That would give it redundancy in links, and if one of the 6500s bit the dust, they would still have access. But you would not be able to manipulate routing to to speak since you only have one unit instead of two.

If I was CompanyA, I would have redundant with 2 links in an port-channel (you can always use more), and

like I said, if one of the 6500 series switches died, the client would still have access.