CertHead

Network Implementation — Network+ practice questions

Domain 2 of the CompTIA Network+ (N10-009) exam. 171 questions on this domain in the full bank — here are four free samples with answers and explanations.

Question 1 · Difficulty 3/5

A network administrator needs to provide Internet access for a small branch office that connects to the Internet through a single ISP link. The branch router has no knowledge of external Internet prefixes. Which type of route should the administrator configure on the branch router so that all traffic destined for unknown networks is forwarded to the ISP? (Select the best answer.)
  1. A host route with a /32 prefix pointing to the ISP gateway
  2. A default route using the network 0.0.0.0 with mask 0.0.0.0 pointing to the ISP gateway
  3. A summary route aggregating all RFC 1918 private address space pointing to the ISP gateway
  4. A floating static route with an administrative distance of 254 pointing to the ISP gateway
Show answer & explanation

Correct answer: B

A default route using the network 0.0.0.0 with mask 0.0.0.0 pointing to the ISP gateway
A default route (0.0.0.0/0) matches any destination not found in the routing table, it is the gateway of last resort, making it the correct solution for forwarding all unknown traffic to the ISP. A /32 host route matches only a single specific IP address and would not cover general Internet traffic. Summarizing RFC 1918 private space covers only private addresses, not the public Internet prefixes the branch needs to reach. A floating static route (with a higher administrative distance) is used as a backup path that activates only when a primary route disappears, it does not inherently forward all unknown traffic, nor would it be appropriate as the primary default here.

Question 2 · Difficulty 3/5

A network engineer is comparing static routing and dynamic routing for a new enterprise WAN deployment with 40 sites, frequent topology changes, and a requirement for automatic rerouting around link failures. Which statement best explains why dynamic routing is preferred over static routing in this scenario? (Select the best answer.)
  1. Dynamic routing protocols encrypt routing updates, making them more secure than static routes by default
  2. Dynamic routing protocols automatically discover network changes and update the routing table without administrator intervention, reducing operational overhead at scale
  3. Dynamic routing protocols consume less router CPU and memory than maintaining a large static route table
  4. Static routes cannot be used in networks that have more than 10 routers, making dynamic routing mandatory above that threshold
Show answer & explanation

Correct answer: B

Dynamic routing protocols automatically discover network changes and update the routing table without administrator intervention, reducing operational overhead at scale
Dynamic routing protocols (such as OSPF or EIGRP) exchange topology information between routers and automatically reconverge when links fail, which directly addresses both the frequent-change and automatic-rerouting requirements at 40 sites. Dynamic protocols do not encrypt routing updates by default, MD5 or SHA authentication must be explicitly configured, so the first distractor is false. Dynamic protocols actually consume more CPU and memory than static routes because they must run protocol processes, maintain neighbor adjacencies, and process updates, the third distractor reverses this reality. There is no Cisco or IETF specification that prohibits static routing above any number of routers; static routing is simply operationally impractical at scale, not technically forbidden.

Question 3 · Difficulty 3/5

Which of the following is a characteristic of distance-vector routing protocols that distinguishes them from link-state routing protocols? (Select the best answer.)
  1. Distance-vector routers maintain a complete map of the entire network topology in a link-state database
  2. Distance-vector routers share their full routing table with directly connected neighbors and select paths based on a metric such as hop count or composite metric
  3. Distance-vector routers use Dijkstra's Shortest Path First algorithm to calculate the best path
  4. Distance-vector routers establish adjacencies and exchange hello packets to synchronize a topology database before forwarding traffic
Show answer & explanation

Correct answer: B

Distance-vector routers share their full routing table with directly connected neighbors and select paths based on a metric such as hop count or composite metric
Distance-vector protocols (such as RIP and IGRP) send routing table updates, vectors of destination plus metric, to directly connected neighbors, and routers choose paths based on that metric (hop count for RIP, composite metric for IGRP). Maintaining a complete topology map in a link-state database is a characteristic of link-state protocols such as OSPF and IS-IS, not distance-vector protocols. Dijkstra's SPF algorithm is used by link-state protocols (OSPF, IS-IS) to compute shortest paths from the topology database. Establishing adjacencies via hello packets and synchronizing a topology database before forwarding traffic describes the neighbor and database-exchange process of link-state protocols like OSPF, not distance-vector behavior.

Question 4 · Difficulty 3/5

A network engineer notices that a Cisco router has two routes to the 172.16.10.0/24 network: one learned via OSPF (AD 110) and one learned via RIP (AD 120). The OSPF metric for the path is 100 and the RIP hop count is 2. Which route will the router install in the routing table? (Select the best answer.)
  1. The RIP route, because a hop count of 2 is lower than an OSPF metric of 100
  2. Both routes simultaneously, using equal-cost load balancing
  3. The OSPF route, because OSPF has a lower administrative distance than RIP
  4. The OSPF route, because OSPF has a lower metric than RIP for this destination
Show answer & explanation

Correct answer: C

The OSPF route, because OSPF has a lower administrative distance than RIP
When a router receives routes to the same destination from different routing protocols, it uses administrative distance, not metric, to select which route to install. OSPF has an AD of 110, which is lower (more trustworthy) than RIP's AD of 120, so the OSPF route is installed. Metrics are only compared between routes learned by the same routing protocol; comparing OSPF's metric of 100 to RIP's hop count of 2 is meaningless because they use different scales. Equal-cost load balancing applies only when the same protocol learns multiple paths with identical metrics to the same destination.

More Network+ domains

Ready to test yourself for real?

The free quiz pulls live questions from the same banks — no account required.

Start the free quiz