300-440 Question 121
Single answerA network engineer is configuring a Cisco router to influence outbound traffic and ensure traffic destined for a specific remote network takes the optimal path. The network uses BGP as the routing protocol. The engineer has multiple options to manipulate path preference. Which method should be used to achieve this goal?
- A
Modify the BGP Local Preference for the specific route
- B
Adjust the BGP Weight attribute on the outbound path
- C
Change the MED (Multi-Exit Discriminator) value for the route
- D
Configure an IP SLA to dynamically adjust the route
Show answer and explanation
Correct answer: A
Explanation
To influence outbound traffic within a BGP-enabled environment, the Local Preference attribute is the most effective and commonly used method. It allows administrators to prioritize specific routes for outbound traffic within an Autonomous System, ensuring optimal path selection. Other options, such as Weight or MED, are used for different purposes, such as inbound traffic control or inter-AS route selection.
- A. Correct.
Correct. The BGP Local Preference attribute is used to influence outbound traffic by setting a higher preference for specific routes within an AS (Autonomous System). This is the correct approach for managing the path preference for outbound traffic.
- B. Incorrect.
Incorrect. The BGP Weight attribute is a Cisco-specific attribute used to influence inbound traffic at the local router level, not outbound traffic across the AS.
- C. Incorrect.
Incorrect. The MED (Multi-Exit Discriminator) is used to influence inbound traffic from neighboring ASes, making it unsuitable for controlling outbound traffic preferences.
- D. Incorrect.
Incorrect. IP SLA is a mechanism for monitoring network performance and can trigger route adjustments, but it is not directly related to BGP path preference attributes.