The IS-IS neighbor relationship between R3 and R1 is not established. According to the information in this figure, what is the possible reason?

The IS-IS neighbor relationship between R3 and R1 is not established. According to the information in this figure, what is the possible reason?

A . The IIH authentication of R3 and R1 failed
B. The System IDs of R3 and R1 are duplicated
C. The lS-Level of R3 and R1 do not match
D. The circuit-type of the interconnection interface of R3 and R1 does not match

View Answer

Answer: A