I'm reviewing a design for MPLS, which had in place C39x5 routers for the CE device. There are a few wrinkles in the design, which involve multiple MPLS providers at each site, with BGP for optimized path and redundancy to the remote MPLS sites. I'm kind of to the point of recommending L3 switches for the CE devices, rather than 39x5 routers, as they are cheaper, more flexible, and the routing requirements are not too major. The issues I'm concerned with now are 1. can the L3 switch handle the load? 2. how to QoS (DSCP-based) the output of the CE router to the PE router for each site? with a router, I could define an output policy, but with the L3 switch, I'm not sure how to handle that?
Here are some general design elements/requirements:
1. 5 - sites MPLS, each site connected to diverse telco peers with BGP routing enabled (ProviderA, ProviderB)
2. 2 - 3560 L3 customer CE "routers" at each site.
3. Provider MPLS uplinks are Gb ethernet, with max BW up to 500 Mbps (1/2 Gbps) at main site.
4. going to leverage telco MPLS-BGP peering to send site routing info back and forth among 5 sites.
5. going to internally peer each sites local CE routers (3750's) with iBGP (for redundancy)
6. each site will have a max of 100 prefix's for a total of 500-1000 max prefix's in the BGP table at any one time.
7. Would like to run EIGRP locally on each sites 3750 routers - just to send loopbacks and one inside LAN subnet info back and forth
8. will run HSRP on the 3750's internal interface, which will face a pair of firewalls on the inside.
Major concerns:
1. Does this sound like it will work with 3560 L3 switches, rather than 39x5 routers?
2. if i went with a smaller 3560 switch (such as an 8-port WS-C3560CG-8TC-S), would there be any CPU concerns since this is a smaller L3 switch?
3. I would like to QoS on output interface to provider MPLS circuit to prioritize gold/silver/bronze traffic over MPLS. not sure how to do that.
4. anything else i may have missed? what might i typically need on this circuit that would be a dead end with the L3 switch option? For example, VRF functionality for multiple routing domains at each site or NAT (which i don't foresee).
thx in advance,
Will
