spanning tree

[carl_townshend]

How can I force one of my switches to block a port for redundancy, rather than spanning tree deciding automatically ?

thanks

[Bobby Thekkekandam]

Configuring the port cost to a higher value would achieve what you are looking for.

For example, for PVST+, we configure the PVST+ port cost for a VLAN on a port (assuming CatOS in this example)

set spantree portvlancost {mod/port} [cost cost] [vlan_list]

You can find more information in this link:

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat6000/sw_8_5/confg_gd/spantree.htm

HTH,

Bobby

[Francois Tallet]

You can configure STP parameters (cost, priority) to influence the decision the algorithm will take so that it blocks a particular port. But if you want to override the STP, the simplest is to shut down the port! ;-)

Flexlink is the only L2 feature that I can think of right now that does not rely on STP, but it only works on very specific scenarios.

Regards,

Francois

[carl_townshend]

Hi there, thanks for the reply, If I have already set up my network, and im basically going to plug the last switch into the first the create the loop, would spanning tree block the port on my last switch ?

[carl_townshend]

Hi there

Can anyone tell me also where I can see which switch is currently acting as the root bridge, and do you change the priority of the switch, or is it a port ? and how is this done ?