Refer to the exhibit and the partial configuration of switch SW_A and SW_B.
STP is configured on all switches in the network. SW_B receives this error message on the
console port:
00:06:34: %CDP-4-DUPLEX_MISMATCH: duplex mismatch discovered on FastEthernet0/5 (not
half duplex), with SW_A FastEthernet0/4 (half duplex), with TBA05071417 (Cat6K-B) 0/4 (half
duplex).
What is the possible outcome of the problem?
A.
The root port on switch SW_A will automatically transition to full-duplex mode.
B.
The root port on switch SW_B will fall back to full-duplex mode.
C.
The interfaces between switches SW_A and SW_B will transition to a blocking state.
D.
Interface Fa 0/6 on switch SW_B will transition to a forwarding state and create a bridging loop.
Explanation:
If switch B misses several BPDUs on the port Fa0/5 due to the duplex mismatch it will assume the
path to the root via Fa0/5 is lost and it will put the port Fa0/6 in forwarding state.
Reference:
CCNP Self-Study CCNP BCMSN Official Exam Certification Guide Fourth Edition, Chapter 8:
Traditional Spanning Tree Protocol, p. 185.