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New Member

spanning tree ports

I am a little confused, I have been reading my cisco book, Can anyone tell me the difference between the root port, and a designated port ?, say I had 4 switches, and they were connected in a loop, how may designated ports and root ports would there be ?

thanks

Carlos

2 REPLIES
New Member

Re: spanning tree ports

can anyone help !!

VIP Purple

Re: spanning tree ports

Hello,

let´s say you have 4 switches which are connected as indicated by you:

Switch1 <--> Switch2 <--> Switch3 <--> Switch4 <--> Switch1

Let´s now assume that Switch1 is the root switch. The concept of root and designated port can be described as following: a root port is the port on a non-root switch pointing to the root switch. A designated port is a port leading away from the root switch.

So, keeping the above in mind, the switch ports indicated would be as following:

Switch1 (Designated Port) <--> (Root Port) Switch2 (Designated Port) <--> (Root Port) Switch3 (Designated Port <--> (Root Port) Switch4 (Designated Port/Blocked) <--> (Designated Port/Blocked) Switch1

As you can see, the root switch has only designated ports, because a root port would be the port pointing towards the root, which is not the case for either port on the root switch.

Does that make sense ?

Regards,

GP

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