Avoiding High-Delay ISP Link
Question
An engineer configured two routers connected to two different service providers using BGP with default attributes.
One of the links is presenting high delay, which causes slowness in the network.
Which BGP attribute must the engineer configure to avoid using the high-delay ISP link if the second ISP link is up?
Answers
Explanations
Click on the arrows to vote for the correct answer
A. B. C. D.D.
The BGP attribute that the engineer must configure to avoid using the high-delay ISP link if the second ISP link is up is the "MED" (Multi-Exit Discriminator) attribute.
When there are multiple links to the same destination, BGP uses several attributes to select the best path. These attributes can be divided into two categories: well-known and optional.
The well-known BGP attributes include the AS-PATH, NEXT-HOP, LOCAL_PREF, and ORIGIN. These attributes are understood by all BGP routers.
The optional BGP attributes include the WEIGHT, MED, and COMMUNITY attributes. These attributes are not mandatory, and their use depends on the network administrator's configuration.
In this scenario, the engineer is facing a problem with one of the links having high delay, causing slowness in the network. Therefore, the engineer must configure BGP to avoid using the high-delay ISP link if the second ISP link is up. To accomplish this, the engineer can manipulate the MED attribute.
The MED attribute is used to influence the path selection process when there are multiple paths to the same destination through different Autonomous Systems (ASes). The lower the MED value, the more preferable the path.
In this case, the engineer can configure the MED attribute on the router connected to the high-delay ISP link to assign a higher MED value than the router connected to the second ISP link. This will make the router connected to the second ISP link the preferred path to reach the destination.
In conclusion, the BGP attribute that the engineer must configure to avoid using the high-delay ISP link if the second ISP link is up is the MED attribute. The engineer can assign a higher MED value on the router connected to the high-delay ISP link to make the second ISP link the preferred path to reach the destination.
