static mac

[sbrobak]

Say you have two Catalysts switches (3500xl) interconnected. A server-cluster is connected to both switches for redundancy - one server to the first switch and the second server to the second switch. I add static mac entries at the switches for the server-nics - it is the same mac statement pointing to both nic ports + the interfaces where the switches is interconnected. Traffic coming into one switch to the destination (static) mac, will be forwared to the nic port and to the second switch. The second switch will forward the traffic to its connected nic port. Will it also send the traffic back to the first switch?

[donewald]

Static MACs for this type redundancy is dangerous please keep this in mind. To answer your question (yes) the traffic would be sent to each switch. For Server/Cluster redundancy there are Software packages sold (ie. Stonebeat/etc) that allow the server nics to have unique MACs and register both but share a logical Mac that is owned by the primary interface. This is a much better system and way of doing things than with static macs you described.

Hope this helps you,

Don