I have 3 switches. The root switch A and another 2 switches, B and C.
I have 2 wired cables that connect the B and C switches and I would like to change the switch that blocks the stp port. In that case is fast ethernet of switch B the blocking port. I would like the blocking port on switch C and not in switch B.
I need to change the priority or the cost on the ports?
I just want to point out that priority in STP is calculated in opposite manner as in other protocols. That means, that if you want to increase priority at switch B, you should LOWER the value. To decrease the priority on switch C, you should HIGHER the value.
From the information provided I am not sure what your topology looks like precisely.
Inayath is correct, however I think that you are talking about election of the designated ports and not the election of root ports. One thing though - keep in mind, that the cost parameter is added to the cummulative value upon reception of the BPDU and not upon its transmission. Moreover - designated port is that port which is SENDING the best BPDU and that these BPDUs between neighbor ports are compared IMMEDIATELY upon reception (thus not adding anything to the cost parameter).
change the priority of the switches so that: Switch C will have the lowest priority, for example 0 (remember, lower is better in STP), Switch B will have the second lowest priority, for example 4096 and Switch A can keep its default priority (if it's higher than 4096).
You can change the Switch priority for a VLAN by issuing command:
Switch(config)#spanning-tree vlan [exact vlan or range of vlans] priority [priority number]
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.