Cisco CCNA mock exam questions sample test – Question 186

.Multiple routes to a destination already exist from various routing protocols.
Which of the following values is used FIRST to select the route that is inserted into the route table?

A. composite metric
B. administrative distance
C. prefix length
D. hop count

Correct Answer: B

Explanation:
When multiple routes to a destination exist from various routing protocols, the first value to be evaluated is the administrative distance of the source of the route. The following are
examples of default administrative distance values:
The second value to be compared is the composite metric, or any metric value for that matter. It is only used when multiple routes exist that have the same administrative distance.
The prefix length is only used to compare two existing routes in the routing table that lead to the destination, yet have different mask or prefix lengths. In that case, the route with the
longest prefix length will be chosen.
Hop count is ONLY used when comparing multiple RIP routes. It is not the first consideration when multiple routes from various routing protocols exist in a routing table.
Objective:
Routing Fundamentals
Sub-Objective:
Describe how a routing table is populated by different routing information sources
References:
Support > Technology Support > IP > IP Routing > Troubleshoot and Alerts > Configuration Example and TechNotes > Route Selection in Cisco Routers