We recently purchased a Cat 6509-E with all GB so we can connect all servers to this. We also have a 4500 that has the majority of our users connected. Our WAN router is a 3825 (all devices in same data center). What is the best design of connecting all three devices together and which device should be handling the routing? Should the 6509 only be a L2 device? Should I setup Etherchannel (if so, any good sites for this?). Also, can the 6509 run either Cat OS or IOS? Which is preferred?