When two bridges are competing for the root bridge of an IEEE 802.1D spanning tree and both
have the same bridge priority configured, which parameter determines the winner?
A.
Highest-numbered IP interface
B.
MAC address
C.
Device uptime
D.
Root port cost
Explanation:
Select a root bridge. The root bridge of the spanning tree is the bridge with the smallest (lowest)
bridge ID.
Each bridge has a unique identifier (ID) and a configurable priority number; the bridge ID contains
both numbers. To compare two bridge IDs, the priority is compared first. If two bridges have equal
priority, then the MAC addresses are compared. For example, if switches A
(MAC=0200.0000.1111) and B (MAC=0200.0000.2222) both have a priority of 10, then switch A
will be selected as the root bridge. If the network administrators would like switch B to become the
root bridge, they must set its priority to be less than 10.http://en.wikipedia.org/wiki/Spanning_tree_protocol