300-410 Question 150
Select 2An enterprise network is experiencing suboptimal routing due to multiple paths being available between two branches. The network administrator wants to configure path manipulation to influence outbound traffic preferences on branch routers. Which of the following methods can be used to achieve this?
- A
Use route maps to modify BGP attributes such as Local Preference.
- B
Apply an outbound distribute list to filter specific prefixes.
- C
Configure a static route with a lower administrative distance.
- D
Use policy-based routing (PBR) to define preferred next hops.
- E
Modify the MED (Multi-Exit Discriminator) attribute on incoming routes from the ISP.
Show answer and explanation
Correct answers: A, D
Explanation
To influence outbound traffic preferences, network administrators can use tools like modifying BGP Local Preference via route maps or implementing Policy-Based Routing (PBR). BGP Local Preference directs traffic to a specific exit point, while PBR provides granular control over traffic flow. Other options, such as distribute lists or MED, do not address outbound traffic directly or are focused on inbound traffic manipulation.
- A. Correct.
Correct: Modifying BGP attributes like Local Preference using route maps is a valid method to influence outbound traffic, as Local Preference is used to prefer a specific exit point for traffic.
- B. Incorrect.
Incorrect: Outbound distribute lists are used for prefix filtering but do not directly influence path selection or outbound traffic preferences.
- C. Incorrect.
Incorrect: Static routes with a lower administrative distance could influence path selection but are not a scalable or dynamic solution for outbound traffic manipulation in this scenario.
- D. Correct.
Correct: Policy-based routing (PBR) allows administrators to define traffic flow based on criteria like source or destination, making it a valid way to influence outbound traffic.
- E. Incorrect.
Incorrect: Modifying the MED attribute affects inbound traffic preferences and is not used for outbound traffic manipulation.