Disabling STP - Port state

[jimmy.ulloa]

Hi guys! have a question… if STP is disabled for a VLAN, what will be the state of the ports belonging to that vlan?

[Reza Sharifi]

Hi,

Be careful, as disabling STP can cause loops if you have redundant links.

From Cisco STP doc:

Note: By default, spanning tree runs on every port. The spanning tree feature cannot be turned off in switches on a per-port basis. Although it is not recommended, you can turn off STP on a per-VLAN basis, or globally on the switch. Extreme care should be taken whenever you disable spanning tree because this creates Layer 2 loops within the network.

link:

http://www.cisco.com/c/en/us/support/docs/lan-switching/spanning-tree-protocol/5234-5.html

HTH