[c-nsp] quick spanning tree question

[Tassos Chatzithomaoglou]

Unless the other side of Gi0/46 is blocked, i don't think it's an issue 
to see traffic on a designated port.
On the other hand, if this switch has dual uplinks to the pri/sec root 
switches, then somewhere else there must be a blocked port.

-- 
Tassos


Cord MacLeod wrote on 27/03/2010 08:47:
> 3 days ago traffic started showing up on the trunk port connecting my top of rack switches.  Each of these switches has it's own better trunk path to the root bridge.  I can't see why any traffic at all would traverse these links unless the other trunk on g0/45 was down, which it isn't.  Also, spanning tree doesn't claim any topology changes.
>
> switch3#sh spanning-tree root port
> VLAN0001         GigabitEthernet0/45
> VLAN0100         GigabitEthernet0/45
> VLAN0101         GigabitEthernet0/45
> VLAN0102         GigabitEthernet0/45
> VLAN0120         GigabitEthernet0/45
> VLAN0200         GigabitEthernet0/45
> VLAN0231         GigabitEthernet0/45
> VLAN0250         GigabitEthernet0/45
> VLAN0321         GigabitEthernet0/45
> VLAN0450         GigabitEthernet0/45
> VLAN0777         GigabitEthernet0/45
> VLAN0888         GigabitEthernet0/45
> switch3#
>
> All vlans read same the Root and Desg port.
>
> VLAN0101
>    Spanning tree enabled protocol ieee
>    Root ID    Priority    24677
>               Address     0017.e1d6.e111
>               Cost        4
>               Port        45 (GigabitEthernet0/45)
>               Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
>
>    Bridge ID  Priority    32869  (priority 32768 sys-id-ext 101)
>               Address     001e.1494.4000
>               Hello Time   2 sec  Max Age 20 sec  Forward Delay 15 sec
>               Aging Time 300
>
> Interface        Role Sts Cost      Prio.Nbr Type
> ---------------- ---- --- --------- -------- --------------------------------
> Gi0/45           Root FWD 4         128.45   P2p
> Gi0/46           Desg FWD 4         128.46   P2p
>
> Any ideas?
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