[c-nsp] quick spanning tree question

[Yuri Bank]

On Fri, Mar 26, 2010 at 11:47 PM, Cord MacLeod <cordmacleod at gmail.com>wrote:

> 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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Have you checked the type of traffic traversing the trunk between the top of
rack switches? Perhaps that could give you a clue as to why this is
happening. ( Maybe some kind of broadcast traffic?).

-Yuri