designated cost 0 in STP

[mahesh18]

Hi Everyone,

Need to confirm below

when we do sh spanning tree vlan on switch

Port 12 (FastEthernet0/12) of VLAN0020 is root forwarding

   Port path cost 19, Port priority 128, Port Identifier 128.12.

   Designated root has priority 24596, address 000d.28bc.fd80

   Designated bridge has priority 24596, address 000d.28bc.fd80

   Designated port id is 128.12, designated path cost 0

   Timers: message age 16, forward delay 0, hold 0

   Number of transitions to forwarding state: 1

   Link type is point-to-point by default

   BPDU: sent 6, received 85529

Port 12 is going to root bridge.

Need to confirm below

designated cost 0   does this mean cost to reach switchs own port 12?

thanks

mahesh

[Reza Sharifi · Accepted solution]

Hi Mahesh,

designated cost 0   does this mean cost to reach switchs own port 12?

That is correct. The cost to switch itself is 0.  If you go to the next switch that is connected to this switch via Fast Ethernet, the cost should be 19.

HTH

Reza

[mahesh18]

Hi Reza,

Thanks again for your help.

Sorry for late reply

Regards

MAhesh