300-445 Question 223
Select 3A global enterprise network is experiencing intermittent issues where specific branch offices report slow application performance. Upon investigation, it is determined that these issues are related to congestion on MPLS links and abnormal TCP retransmissions. As the network administrator, you are tasked with configuring alert rules to proactively monitor and detect these conditions. Which alert rules should you configure to address these issues?
- A
Set an alert rule to monitor TCP retransmission rates using NetFlow data.
- B
Configure an alert rule to track MPLS link utilization exceeding a predefined threshold.
- C
Create an alert rule to track changes in the state of the BGP routing table.
- D
Enable an alert rule to monitor SNMP error counters on edge routers.
- E
Set an alert rule to monitor syslog messages for VPN tunnel failure notifications.
Show answer and explanation
Correct answers: A, B, D
Explanation
To address the network issues related to MPLS congestion and abnormal TCP retransmissions, it is important to configure alert rules that monitor TCP retransmission rates, MPLS link utilization, and SNMP error counters. These metrics directly reflect the conditions causing the performance issues, allowing for timely detection and resolution. Monitoring BGP state or VPN tunnels, while valuable for other scenarios, does not address the specific problem described here.
- A. Correct.
Correct. TCP retransmission rates can indicate network congestion or packet loss. Monitoring these rates using NetFlow data helps identify and address performance issues.
- B. Correct.
Correct. High MPLS link utilization is a key indicator of congestion. Setting an alert for utilization above a threshold ensures proactive detection.
- C. Incorrect.
Incorrect. While monitoring BGP routing table changes is important, it is not directly relevant to the congestion or TCP retransmission issues described in this scenario.
- D. Correct.
Correct. SNMP error counters can reveal issues such as packet drops or interface errors, which may contribute to congestion and retransmissions.
- E. Incorrect.
Incorrect. Monitoring VPN tunnel failures is useful for identifying connectivity issues but is unrelated to MPLS congestion or TCP retransmission problems in this scenario.