CompTIA Network+ Practice Test

In the route entry R 10.10.30.0/24 [120/1] via 10.10.50.2, what does '120' represent?

1. Administrative distance

2. Subnet mask length

3. Metric value

4. TTL value

The correct answer is: Administrative distance

In the route entry R 10.10.30.0/24 [120/1] via 10.10.50.2, the '120' signifies the administrative distance. Administrative distance is a value that routers use to determine the reliability of a route source. It allows routers to rank routes learned from different routing protocols, thereby helping them select the best path when multiple routes are available to the same destination. For example, an administrative distance of 120 typically corresponds to routes learned via external routing protocols, such as RIP. The lower the administrative distance, the more trusted the route. Therefore, in this case, a value of 120 indicates a relatively less preferred path compared to other sources that may have a lower administrative distance. The other values listed in the entry serve different purposes. The subnet mask length (/24) indicates how the network is segmented into smaller subnetworks. The metric value '1' reflects the cost of reaching that route, which gives a measure of distance, but in a different context. Lastly, the TTL (Time to Live) value is associated with packets rather than routing entries, denoting how many hops a packet can take before being discarded.