cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
683
Views
0
Helpful
3
Replies

spanning-tree portfast trunk

admin_2
Level 3
Level 3

I'm having doubt about a config that I'm not sure of...

I always tought that spanning-tree portfast sould be use on port that connect host (access)

Do you know why I would have this command

spanning-tree portfast trunk on a interace connecting 2 switch? Is it something desirable?

Merci,

3 Replies 3

Tarun Lohumi
Cisco Employee
Cisco Employee

spanning-tree portfast should be enabled only on access-ports that connect to workstations because enabling them on trunk ports could cause accidental STP loops. That being said there are situation in which you connect to end servers with a trunk port & you dont want that port to go through the usual 50 sec delay in STP state transistions. For such cases we can enable 'stp portfast trunk' on a trunk port which would cause the trunk to behave exactly as a access port connected to a workstation skipping the STP delay.

Hope that helps !!

Mark Yeates
Level 7
Level 7

I would recommend removing the command from the interface if possible. You could run into some serious problems in the future using portfast on an uplink. More than likely someone put it there for faster convergence when/if the link went down.

HTH,

Mark

I have to agree with Mark with an addition, if you want faster convergance in case of a primary uplink failure - then portfast it not the solution. You might want to consider running RPVST or enabling uplinkfast for fast convergance in a failure situation.

HTH>

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community: