Which two of these are used in the selection of a root bridge in a network utilizing Spanning Tree
Protocol IEEE 802.1 D? (Choose two.)

A.
Designated Root Cost

B.
bridge ID priority

C.
max age

D.
bridge ID MAC address

E.
Designated Root Priority

F.
forward delay

Explanation:
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.