Is there any chances of two bridges having the same root ID and thus will be voted as the root bridge based on their respective cost. If cost is the factor, both "root candidate" might have different cost in the whole of the network, thus causing other bridges in the network to elect different root
Is that possible?
No.
The value used for selecting which bridge becomes root bridge in a spanning tree is created from the 16 bit root priority /and/ the 48 bit MAC address.
Since MAC addresses are guaranteed to be unique it is not possible (according to the standard) to have a clash.
Think of it like this:-
x = root priority hex digit y = bridge MAC address hex digit
Bridge ID = xxxx.yyyy.yyyy.yyyy
Radia says that if the root ID is the same, we move on to the cost to decide who is to be the root. Am I right that when she says that she is actually refering to the same switch but not different switches with the same ID?
In short, packets with same root ID going into a different ports of another switch actually came from the same originating switch?
snipped-for-privacy@hotmail.co.uk wrote:
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