Layer 3 to the Access Layer and MPLS Design Considerations

[cbeswick]

Hi,

We are about to install a new network consisting of Cat 4500s with Sup7E at the Access Layer, with Nexus 7000 at the Distribution and Core layers.

We have 14 floors with at least three 4500s on each floor. Within the office block where the Access Layer and Distribution Layer reside we need to support secure borderless networking using 802.1x to place users from different parts of the business into segregated networks at layer 3.

All switches will have the feature sets to support MPLS/ VRF / OSPF / EIGRP / BGP etc.

We quickly dismissed the idea of using VRF-Lite due to the sheer number of Vlans we would need to managage and maintain,  the point to point links alone just to get one additional VRF on each floor required far too many Vlans.

As a result we are now considering deploying MPLS. The obvious benefits include scalability and manageability, the fact that all switch to switch links can now be routed, instead of having to using SVIs.

My query is one of design surrounding MPLS and how this maps to an enterprise network with a routed access layer. Do Cat 4500s become the CEs and take part in MPLS / BGP and Label Distribution, or does the BGP peering and Label Distribution only occur between the Distrubtion - Core - Distrubtion layers, mapping to the PE - P - PE topology in an ISP environment, the access layer simply uses the IGP (OSPF in this case) to learn routes ?

Any help would be greatly appreciated.

Chris.

[aacole]

Hi Chris,

Do you need any L2 paths between different 4500's ? If you dont then I'd suggest pushing the MPLS out to the 4500's. Then you can pre-populate the 4500's with a number of VRF's across each edge node, and then apply vlan's as appropriate to the VRF's as the need arises. This should be quite straightforward.

If you need L2 paths between the 4500's, then you could could either use MPLS PW, VPLS (if supported) or vrf lite back to the distribuition, each of which brings its own complexities.

Andy

[cbeswick]

Hi Andy,

Thanks for your response.

I have been doing a little bit more research it seems the Cat 4500s do not support MPLS!! Nor do Cisco have any plans to support it on this platform. I find this a little rediculous considering the level that Cisco are pitching this platform. With the Sup 7E only VRF Lite is supported, with plans to support EVN (which still uses trunk links for logical separation).

So it looks like we are going to have to go back to the drawing board.

(perhaps we should have gone HP or Juniper!)

Chris.

[HumanTorch]

is there documentation that says the 4500-E doesnt support MPLS?

what about the Sup-8E? with Advanced Enterprise licensing?