Re: Spanning-tree root bridge

[Fernando Carvalho <fernando.cagica@xxxxxxxxxxx>]

You mean spanning.tree mst 1 root <primary|secondary>.
this command runs one macro that will decrease the priority of the 
switch where it is applied to a value that makes it become the root (but 
this will be done only when you apply the command, if in the future some 
new swich is added to the network with a lower priority than the root 
then this command is not going to work again by itself, the new switch 
will become the new root, also when you type "show run" you will not see 
the command in the output config the same way you entered it (just 
try)... see the following link:

http://www.cisco.com/en/US/docs/switches/lan/catalyst3560/software/release/12.2_25_see/command/reference/cli3.html#wp1946716

so both commands make one switch become the root, which should you use 
depends on what you are requested to do....

HTH

akyccie schrieb:
> Question: SW1 should be the root about mst Intance (1)
>
> There are two way to achive the same
>
> a).
>
> SW1
> Spanning-tree mst 1 priority 0
>
> b).
> sw1
> spanning-tree mst 1 root bridge
>
> Is there any difference here, which one is right way from exam point of view
>
>
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--
Fernando Carvalho 
CCIE #20126 (R&S)