300-445 Question 218
Select 3Your organization has deployed a network monitoring solution that supports alert rules based on various network conditions. You are tasked with creating an alert rule to detect anomalies in the BGP routing table that could indicate instability in the network. Which of the following conditions should you configure in the alert rule to achieve this?
- A
Monitor the number of BGP route flaps within a specific time interval
- B
Track TCP retransmissions across critical application servers
- C
Set a threshold for excessive BGP route withdrawals
- D
Monitor MPLS label stack depth changes
- E
Enable alerts for significant increases in the size of the BGP routing table
Show answer and explanation
Correct answers: A, C, E
Explanation
To detect anomalies in the BGP routing table, it is essential to monitor conditions that directly affect the stability and behavior of BGP. Metrics such as route flaps, excessive withdrawals, and unexpected table size changes provide valuable insights into network stability and potential issues. Other conditions, such as TCP retransmissions or MPLS label stack changes, are unrelated to BGP and would not contribute to identifying these anomalies.
- A. Correct.
Monitoring the number of BGP route flaps can help identify instability in the BGP routing table, as frequent changes in route advertisements indicate network issues.
- B. Incorrect.
Tracking TCP retransmissions is unrelated to BGP routing table anomalies but is useful for identifying application-layer issues.
- C. Correct.
Setting a threshold for excessive BGP route withdrawals is crucial for detecting potential instability, as a high number of withdrawals can indicate network changes or failures.
- D. Incorrect.
Monitoring MPLS label stack depth changes is not directly related to BGP routing table stability, as this pertains to MPLS-specific operations.
- E. Correct.
Significant increases in the size of the BGP routing table could indicate abnormal routing behavior or potential misconfigurations, making this an important condition to monitor.