A basic overview of our current network design for core and distribution is as follows:
6506-E chassis in VSS
6509-E chassis single sup connected to each of the 6506 chassis in the core.
We are looking to replace the VSS in the core with Nexus 7K switches. Since the Nexus switches are not virtual by nature, I have to consider a HA protocol like HSRP or GLBP. Currently our links between the Core and Dist are L3 Point-To-Point. We wish to maintain this configuration in the new design. Since the two links on the Dist side are port-channels we currently have 2Gbps throughput. If I use HSRP with LACP one link goes into suspended mode, therefore only giving us 1Gbps throughput. With GLBP we continue to have 2Gbps. From what I can tell, ECMP (Equal-cost multipath) is enabled and should be in effect at this point, but I cannot find a way to prove this since I do not have another 6509 for distribution (my test distribution switch is just a 3560).
My question is this...
What is the best practice way to go in this situation? Should we allow STP to provide a look free environment and use priorities to determine the path (using HSRP and LACP) or should I use GLBP and have an active-active scenario from DIST to Core? Any suggestions on a solid way to test that load balancing is in fact working properly?
Excuse me if I misspeak on anything here as this is my first solo attempt at replacing a core. I've been living in the distribution and access layers for many years now.
Thank you in advance for any and all feedback.