When I issued "sh spanning-tree vlan 1"command,I found that here's a port status was very strange:BKN,and I couldn't find it's info on CCO,the result of show command as below:
Gi2/11 Root BKN*200000 240.75 P2p *PVID_Inc
Gi2/13 Desg FWD 4 128.77 P2p
Gi2/14 Altn BLK 4 128.78 P2p
Fa3/47 Desg FWD 19 128.175 P2p
Fa3/48 Altn BLK 19 128.176 P2p
Po1 Root FWD 3 128.833 P2p
G2/11 is a trunk port to a neighbor which is 6509 running with CatOS,and it was the pre-root of vlan1 of priority 8192.For some reasons I just assgined vlan1's root to another IOS switch by issued "spanning-tree vlan 1 root primary" command.After this,I found that priority has became to 12289.I had checked the new root switch to make sure its role was correct.But I also curious why the root changed?because the priority of new root was higher than pre-root,but it really changed.Any reply will be very appreciated.
VLAN0001
Spanning tree enabled protocol ieee
Root ID Priority 12289
Address 000d.bdf8.9340
Cost 22
Port 833 (Port-channel1)
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
