Scenerio:
Does anyone know the proper configuration/design when using dual nics in a cisco switch environment. For example, if you have two nics in an hp server configured for either fault tolerance or load balancing. There are a few ways you can go about doing this on the cisco side. You can have both network cables plug into the same switch and I can create an etherchannel where both ports are bound together for true aggregate bandwidth. The other preferred option is to have one nic plug into one switch and the other nic into a second switch. This way if either switch or nic fails you still maintain connectivity.
Issue/question:
If you go with the 2nd option then you need to be careful because when you use fault tolerance most of the times you have to use a virtual mac address. This virtual mac address will show up on both switch ports. As I’m sure you all know switches forward frames according to their layer 2 address. Is there any special configurations that you need to take into consideration when using dual nics across different switches. I think this is causing a big issue with spanning tree seeing that the same mac is on two different switch ports. This also becomes an even bigger issue if portfast is turned on at both ports. Any design help would be greatly appreciated.
– Mark