I've got portfast configured on all end-user ports on several 2950s, which are redundantly hosted by two 6513s. I am using mst and have nearly 200 vlans configured. I have around 90 2950s. I am running two instances of mst and have the vlans spread equally over them both. I keep get topology change notifications at the cores from two sources: a particular 2950 (don't know why) and a L2 port-channel. Any ideas how on what info I need to look at to figure out what is causing these TCNs.
Is it possible that if vlans from both mst instances are running on a switch, then only vlan(s) from one instance are running would cause a TCN? Thanks