In the evaluation of an RSTP configuration BPDU, which two values are contained in the Bridge ID value? (Choose two)
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A. B. C. D.BC
In RSTP (Rapid Spanning Tree Protocol), each bridge in the network is identified by a unique Bridge ID value. This value is used by RSTP to determine the root bridge and to calculate the shortest path to the root bridge. The Bridge ID value is comprised of two parts: the Bridge Priority and the MAC address of the bridge.
The Bridge Priority is a 2-byte value that is used to determine the root bridge in the network. The bridge with the lowest Bridge Priority value becomes the root bridge. By default, the Bridge Priority is set to 32,768, but it can be changed to any value between 0 and 65,535. Lower values indicate a higher priority, and therefore a greater likelihood of becoming the root bridge.
The MAC address of the bridge is a 6-byte value that uniquely identifies the bridge. The MAC address is used to break ties when two or more bridges have the same Bridge Priority. The bridge with the lowest MAC address becomes the root bridge.
So, to answer the question, the two values contained in the Bridge ID value are the Bridge Priority and the MAC address of the bridge. Option A, root bridge address, is incorrect because the Bridge ID value does not contain the address of the root bridge, only the Bridge Priority and the MAC address of the bridge. Option B, priority, is correct because the Bridge Priority is one of the values contained in the Bridge ID. Option C, originating bridge address, is incorrect because the Bridge ID value does not contain the address of the bridge that originated the BPDU, only the Bridge Priority and the MAC address of the bridge. Option D, port number, is incorrect because the Bridge ID value does not contain the port number, only the Bridge Priority and the MAC address of the bridge.