To create a backup route that is only used if the primary route fails, which command would be appropriate?

To create a backup route that is only used if the primary route fails, which command would be appropriate?

• A. ip route 172.16.1.0 255.255.255.0 s0/0/0 1
• B. ip route 172.16.1.0 255.255.255.0 s0/0/0 121
• C. ip route 172.16.1.0 255.255.255.0 s0/0/1 21
• D. ip route 172.16.1.0 255.255.255.0 s0/0/1 100

Answer: (B)

The command that creates a backup route utilized only when the primary route fails involves setting an administrative distance, which determines the trustworthiness of a route. The command that includes "121" as the administrative distance is appropriate for the purpose of establishing a backup route. The administrative distance is a value assigned to a route that informs the routing table about the reliability of a route. Standard administrative distances are typically set to values between 0 (highest priority) and 255 (lowest priority). By assigning a distance of 121 to the backup route, this value indicates that the route is less preferred than routes with a lower administrative distance, specifically those that have a distance of 1 (which is typically used for directly connected networks) or 20 (for EIGRP). Thus, the backup route will only be utilized if the primary route, which has a lower administrative distance, is unavailable. This ensures that the network can maintain connectivity through an alternative path without disrupting the preferred routing. In the other commands, the administrative distances specified do not provide the necessary conditions for a backup route. For example, having an administrative distance of 1 or 100 makes those routes more preferred compared to a route with a distance of 121. Therefore, only the command with

The command that creates a backup route utilized only when the primary route fails involves setting an administrative distance, which determines the trustworthiness of a route. The command that includes "121" as the administrative distance is appropriate for the purpose of establishing a backup route.

The administrative distance is a value assigned to a route that informs the routing table about the reliability of a route. Standard administrative distances are typically set to values between 0 (highest priority) and 255 (lowest priority). By assigning a distance of 121 to the backup route, this value indicates that the route is less preferred than routes with a lower administrative distance, specifically those that have a distance of 1 (which is typically used for directly connected networks) or 20 (for EIGRP). Thus, the backup route will only be utilized if the primary route, which has a lower administrative distance, is unavailable. This ensures that the network can maintain connectivity through an alternative path without disrupting the preferred routing.

In the other commands, the administrative distances specified do not provide the necessary conditions for a backup route. For example, having an administrative distance of 1 or 100 makes those routes more preferred compared to a route with a distance of 121. Therefore, only the command with