We can change both. If we change the port cost, it changes the overall rootpath cost to reach the root bridge.
Port priority comes into the picture at the last if some has changed the priortiy to some vlaue then the default 128, when we have met all the underlying criteria for selecting best link. For example if you have two link coming from an adjacent switch:
The first criteia is the root path cost which will be same.
The second criteria is the lowest mac-address of the sending neighbor switch, which again will be same.
Then comes the port priority, which is bydefault 128 and will be same.
If all the above criteia is same than the port ID comes at the last. The lower the port ID and more favourable link.
The same goes with the port priority. The lower the port priority i.e less than 128 and more favourable the link.
This is actually a pretty cool feature, i didn't even know it existed until I was looking for a solution to advertise a subnet (prefix in BGP talk), only if a certain condition existed. This is exactly what conditional advertisements does
j ai une question j ai achete un routeur cisco 887VA-k9 , je le configuré avec la configuration ci- dessous
si je le lier avec mon pc portable sur l un de ses ports directement ça marche toute est bien ( la connexion internet + m...
Attached policy provides CLI access to the Cisco 4G router over text messaging. Two files are in the attached .tar file:
2. PDF with instructions on how to load and use the .tcl file.