STP and Port channel

[SPYME.GOOGLE]

Hi

I have a question regarding STP port cost.

1. If i aggregate 4 gig links into a port channel what will be the cost of this channel. The default cost of gig link is 4 by default.

[glen.grant]

It will be 4 then because an etherchannel is considred a single link as far as STP is concerned.

[Francois Tallet]

It will be 3 on IOS without the short cost (anything between 1 gig and 10 gig is 3 I think).

You can migrate your network to 32 bit cost (spanning-tree extend system-id). That will give you much more granularity.

Regards,

Francois