I have a data center LAN with two Hybrid mode 6509's with MSFC's at the core and a series of 2950 T switches set up as access layer switches. The 2950's have links back to both of the 6509's. I have uplinkfast configured on all of the 2950's. When I did maintenance on the 6509's and took down the primary switch, which is root bridge for all VLAN's the The other 6509 configured as backup root bridge for all VLANS took over and I lost only a couple of pings. When I brought the primary switch back up after the maintenance was complete it appears that the 2950's started forwarding on the primary link and blocked the backup link before the primary switch had started to forward on any ports. The result of this behavior was that I had a 90 second outage rather than the 10 to 30 second outage I anticipated. Is there any work around for this? thanks for any insight you all might have on this.