[c-nsp] 3550 learning state

[Daniel Hooper]

Hi,

I have a 3550-48-EMI running 2 MST spanning tree instances.

What's happening is that when an ethernet interface is connected or disconnected 5 of the ports on the switch move back to a learning state.

The ports that are changing to a learning state are both trunk & access ports.

I'm not too familiar with spanning-tree and this is my first attempt to get it going, I don't believe this is normal though.

This is the config I am running on this particular switch that is doing weird things:

!
spanning-tree mode mst
no spanning-tree optimize bpdu transmission
spanning-tree extend system-id
!
spanning-tree mst configuration
 instance 10 vlan 50, 69-70, 92-96, 98-99, 291, 350, 498-509, 550, 603
 instance 10 vlan 605-606, 701, 703, 750, 761, 800-802
 instance 15 vlan 1-49, 51-68, 71-91, 97, 100-290, 292-349, 351-497, 510-549
 instance 15 vlan 551-602, 604, 607-700, 702, 704-749, 751-760, 762-799
 instance 15 vlan 803-4094
!
spanning-tree mst hello-time 4
spanning-tree mst 10 priority 61440
spanning-tree mst 15 priority 61440
!

!
interface FastEthernet0/12
 description Uplink to Somewhere
 switchport trunk encapsulation dot1q
 switchport mode trunk
 switchport nonegotiate
 shutdown
 no cdp enable
 spanning-tree mst 10 port-priority 32
 spanning-tree mst 15 port-priority 64
end

!

!
interface FastEthernet0/48
 description Uplink to Somewhere
 switchport trunk encapsulation dot1q
 switchport mode trunk
 speed 100
 duplex full
 spanning-tree mst 10 port-priority 64
 spanning-tree mst 15 port-priority 32
end
!

Any help appreciated!

-Dan