When is required to make a full redundancy for 4500R/6500 modular switches with chassis redundancy versus modules redundancy?
In my opinion it is necessary only if is required 24x24 ensuring. When there aren’t time gaps to shutdown equipment for maintenance jobs. Chassis redundancy is more expensive (may be not so much) and more complex in management. And this solution excludes some possibilities, for example Etherchannels uplinks to different modules in chassis. A 48 port 2960G/3560G switch can be connected with 4 ports Etherchannel to 2 different modules in 4500/6500 switch. We have got 12:1 oversubscribing and a good resiliency