LAN Redundancy Port Cost Not Changing

[cyberWolf]

LANGood day,

I'm new to networking and currently working on an activities LAN Redundancy, it's doing good until such I have to change port cost in the non-root switches, but it won't work.

When I type --> 

S1(config)#int f0/1

S1(config-if)#spanning-tree cost 19

S1(config-if)#end

the port f0/1 is being updated in the table --> show spanning-tree did not change.

I am not sure what is the problem why it's not changing.

Below is the credentials for packet tracers

Password : cisco

Enable: class

[Georg Pauwen · Accepted solution]

Hello,

I think you have to specify the Vlan:

S1(config-if)#spanning-tree vlan 1 cost 53
S1(config-if)#end
S1#
%SYS-5-CONFIG_I: Configured from console by console
sh spanning-tree interface fastEthernet 0/1
Vlan Role Sts Cost Prio.Nbr Type
---------------- ---- --- --------- -------- --------------------------------
VLAN0001 Altn BLK 53 128.1 P2p
S1#

[cyberWolf · Accepted solution]

Hi @Georg Pauwen ,

It works, I did specify vlan 1 after the spanning-tree. and I was able to change the port cause on the table itself.

Appreciates.

[paul driver · Accepted solution]

Hello
Just like to note, be careful with this command in a production network, make sure you understand what you are doing. As changing stp port cost effects the entire stp topology no just the that specific port, if you want to effect how downstream switch elect their stp root  then port priority would be a more viable option

int x/x
spanning-tree vlan xx port-priority xx

[cyberWolf]

Hi  @Paul ,

Well noted truly appreciate!

Thank you for the additional info. I believe it is truly helpful while doing my succeeding activities.

Thanks,