Spaning-tree | Trunk

Unanswered Question
Dec 29th, 2007
User Badges:

Hi netpro,

when i type " show int trunk " i got this result. this is something wrong .

Port Vlans in spanning tree forwarding state and not pruned

Gi1/1 none

Gi2/1 1,10-11,20,22,30,40,50-51,60-61,70-71,80-84,90-94,100-102,110-113,120,130,140-142,144,150-155,188-189,192-195,198-200,210,220,225,301-302,311,400-402,405

Fa4/46 210,220,225

Fa4/48 210,220,225

Fa5/48 210,220,225


Port Name Status Vlan Duplex Speed Type

Gi1/1 connected trunk full 1000 1000BaseSX

your reply will be highly appreciated.




  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 4 (1 ratings)
glen.grant Sat, 12/29/2007 - 12:22
User Badges:
  • Purple, 4500 points or more

Please reply why you think something is wrong ... G1/1 may not have anything in the forwarding statement if there is an alternate path to the same device . Do a show spanning-tree blockedports " and see if everything is blocked across that link .

ney25 Sat, 12/29/2007 - 23:24
User Badges:

Hi Glen,

thanks for reply, the reason i said that was because, i have enable the pruning and spanning-tree root brigde 8192 and 16382.

so, when i show int trunk . it should be gi1/1 - 1,3,5,7,9 ...etc

gi1/2 - 2,4,6,8,10 ...etc

your reply will be highly appreciated.




Jon Marshall Sun, 12/30/2007 - 11:07
User Badges:
  • Super Blue, 32500 points or more
  • Hall of Fame,

    Founding Member

  • Cisco Designated VIP,

    2017 LAN, WAN

Hi Jackal

If you have VTP pruning enabled it doesn't matter which switch you set as root or secondary, what matters is which ports are in which vlans on the switch at the other end of the trunk link ie.

gi1/1 connects to a switch. Does this switch have any ports that have been allocated to vlan 1,3,5,7,9 etc... If not then the trunk will show "none" as in your output above. Remember that the first line of output says

Port Vlans in spanning tree forwarding state and not pruned

So if you have no ports allocated to any of the vlans on the switch connected to gi1/1 it will prune those vlans from the trunk.

As a test go onto switch connected to gi1/1 and allocate a port into one of your vlans.


ney25 Mon, 12/31/2007 - 03:23
User Badges:

Hi Jon,

thanks for reply, i got it.





This Discussion