Using PVST+ I have two 3550's linked via a Gig uplink (cost 4 to root) and a fas eth uplink (cost 19 to root).
Switch A is my root bridge by lowest priority. If I guard the RP i.e. Gig 0/1 on my root bridge and leave the fast ethernet port unguarded and then change my priority on switch B to be lower I find that Switch B becomes the root bridge. Can I conclude that I must configure 'root guard' on all forwarding ports on my root bridge to protect the integrity of the root bridge ?