NA292

[fucher]

I have a question about links between network devices with two different physical speeds and what the STP cost is. In the example it shows a Gig link and an Fe link on the same network segment. Is the STP cost what ever the highest cost interface allows. So if you have a Gig and an Fe on the same link the cost will be 19?

The answer hints at this but does not explicitly say so.

Thanks in advance

[St. Louis]

I believe this depends on what value you are trying to determine.
If you are trying to determine the root port for a non-route bridge/switch, you add the costs associated with the outgoing interfaces on the way to the root bridge/switch.
If you are trying to determine the cost of a hello packet onto a LAN, you start at the root bridge/switch and add the port costs of the incoming interfaces on the switches/bridges, until you reach the LAN segment in question.
Correct me if I'm wrong or have misunderstood your question.