question reguarding one of your practice test questions

henrock2

2. Which of the following are true concerning the Spanning Tree Protocol in a switched network?
a. The switch with the highest Bridge Priority will be elected root switch.
b. The switch with the lowest Bridge Priority will be elected root switch.
c. The main purpose of STP is to eliminate loops in networks with redundant paths.
d. The main purpose of STP is to share VLAN configuration between switches.


well the answers said it was b,c

but i thought when a switch comes on to the network it thinks that the root is itself? or is that just with VLAN configuration?

or should i think because it just entered the network it does have the lowest priority,it has not be defined by the administrator of its functions and rights...???

Tango_Tango

I am by no means an expert, and I did not see the original question, but the only correct answer to that question would have to be C. The switch with the lowest bridge priority AND the lowest MAC address will be elected root bridge. The default priority is 32,768, so if left unchanged on all of the switches, the bridge with the lowest MAC address will be elected root.
That removes B as a correct answer and leaves C as the most correct.

-B

caibil

the answer is B

Webmaster

The answer is still B and C...

henrock2

yes,the answers are b,c

i copied the question just as it came on the practice test.

thanks for the feed,back

i knew c was the answer,
but i kinda figured b was aswell,it was a multi-check question. I just wanted to know was i on the right track by saying the switch with the lowest priority would be the one that just came on the network and believes that itself is the root. I read over my curriculum alil bit more just to clear myself up. Im currently trying to write my own study guide for me to take around ,i have so much stuff crammed into my head. Anyone suggest any books? i got the ones from ciscopress,and i have some other material that i have been reading.

sikdogg

Tango_Tango wrote:

The switch with the lowest bridge priority AND the lowest MAC address will be elected root bridge. The default priority is 32,768, so if left unchanged on all of the switches, the bridge with the lowest MAC address will be elected root. -B

Your reason above is irrevelent, the question said "the switch with the lowest bridge priority will be elected root bridge" nothing about default priority or if left unchanged. Since the bridge priority has a bigger effect in lowering the bridge ID than the MAC address, the switch with the lower bridge priority will most likely become root. B is correct.

sikdogg

henrock2 wrote:

but i thought when a switch comes on to the network it thinks that the root is itself?

You are correct, when a switch/bridge first come on a network it assumes that it is the root bridge and advertises itself as such. If/when it sees a bridge ID that is lower than its own, it will at that point begin to advertise that lower bridge ID as the root ID in its BPDU. As all switches/bridges compare it own bridge ID to one another, they will eventually elect the device with the lowest bridge ID as the root bridge.