05-12-2009 08:29 PM - edited 03-04-2019 04:44 AM
Hi, What is the meaning of "Prio.Nbr" of Spanning tree output ? What "128.3 /128.18" says
Switch#sh spanning-tree vlan 130 brief
VLAN0130
Spanning tree enabled protocol ieee
Root ID Priority 8192
Address 000b.bf8c.a402
This bridge is the root
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Bridge ID Priority 8192
Address 000b.bf8c.a402
Hello Time 2 sec Max Age 20 sec Forward Delay 15 sec
Aging Time 300
Interface Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
Gi1/3 Desg FWD 4 128.3 P2p
Gi1/18 Desg FWD 4 128.18 P2p
05-12-2009 08:46 PM
Cost priority is self explaining.
Number is the unique port identifier for all ports on all bridges
--> Bridge id + port number
05-12-2009 09:47 PM
Thanks. One thing more, I am confused with Bridge ID. I know the Root ID. Please help me about Bridge ID.
05-12-2009 10:24 PM
BID is priority 8192 + extended ID (vlan 130) + MAC address.
In your case, you're the root, so the two lines of output are the same.
05-20-2009 12:33 AM
Hi, Why Interface No and Port ID is not matching in spanning-tree output ??
Interface Designated
Name Port ID Prio Cost Sts Cost Bridge ID Port ID
-------------------- ------- ---- ----- --- ----- -------------------- -------
FastEthernet0/9 128.10 128 19 FWD 19 32768 cc01.08e4.0000 128.10
FastEthernet0/10 128.11 128 19 FWD 19 32768 cc01.08e4.0000 128.11
FastEthernet0/13 128.14 128 19 FWD 0 32768 cc00.08e4.0000 128.14
FastEthernet0/14 128.15 128 19 BLK 0 32768 cc00.08e4.0000 128.15
FastEthernet0/15 128.16 128 19 BLK 0 32768 cc00.08e4.0000 128.16
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