Refer to the exhibits. R1 and R2 are directly connected and IS-IS routing has been enabled between R1 and R2. R1 generates the above log message periodically.
Based on this output, which statement is true?
A. IS-IS neighbor authentication is failing for Level 2 PDUs only.
B. IS-IS neighbor authentication is failing for Level 2 first and then for Level 1 PDUs.
C. IS-IS neighbor authentication is failing for Level 1 and Level 2 PDUs.
D. IS-IS neighbor authentication is failing for Level 1 PDUs only.
Correct Answer: D