CCNA 2 Routing and Switching Essentials v5 Chapter 7: Routing Dynamically – Check Your Understanding Questions Answers
1. What is the difference between interior and exterior routing protocols?
- Exterior routing protocols are used only by large ISPs. Interior routing protocols are used by small ISPs.
- Interior routing protocols are used to route on the Internet. Exterior routing protocols are used inside organizations.
- Exterior routing protocols are used to administer a single autonomous system. Interior routing protocols are used to administer several domains.
- Interior routing protocols are used to communicate within a single autonomous system. Exterior routing protocols are used to communicate between multiple autonomous systems.
Explanation: Interior gateway protocols (IGPs) are used for routing within an organization having a common administration or autonomous system (AS). Exterior gateway protocols (EGPs) are used by service providers and sometimes by large companies.
2. Which factor directly affects the time to convergence?
- Data link layer protocol used
- Number of hosts
- Size of the network
- Type of applications used
Explanation: The factors that directly affect the time to convergence are the speed of the links, the type of protocol used, and the size of the network. The number of hosts, the applications, and the Layer 2 protocol that is used have no direct impact on the time to reach convergence.
3. Which classless routing protocol supports VLSM and CIDR, supports manual route summarization, and uses the multicast address 224.0.0.9?
- RIPvl
- RIPv2
- OSPF
- EIGRP
4. What are two characteristics of link-state protocols compared to distance vector protocols? (Choose two.)
- They require a lot of hardware resources.
- They know of the network topology from the perspective of their neighbors.
- They compute their own knowledge of the network topology.
- They use hop counts to compute the network topology.
- They flood the routing table periodically.
5. Which classless routing protocol supports VLSM and CIDR, bounded and triggered updates, and uses the multicast address of 224.0.0.10?
- RIPvl
- RIPv2
- OSPF
- EIGRP
Explanation: RIPv1 uses broadcast, not multicast. RIPv2 uses the multicast address 224.0.0.9.
6. Which algorithm is used by the OSPF routing process to construct the SPF tree on a router?
- DUAL algorithm
- Bellman-Ford algorithm
- Dijkstra’s algorithm
- Path vector protocol
Explanation: OSPF routing process uses Dijkstra’s algorithm to construct the SPF tree. DUAL algorithm is used by the EIGRP routing protocol. Bellman-Ford algorithm is used by RIP routing protocol. Path vector protocol is the protocol used by BGP.
7. What is an advantage of OSPF compared to RIP?
- Fast convergence
- Less complexity
- Less CPU processing
- Low memory requirements
Explanation: Link-state routing protocols require more CPU processing and memory to compute the routes using the Dijkstra algorithm. They are more complex but converge much faster than distance vector protocols like RIP.
8. A network administrator has examined the routing table of a router and noted that the entry for the destination network 172.16.4.0/24 begins with the letter D. What does this letter signify?
- The route to network 172.16.4.0/24 is directly connected.
- The route source was learned dynamically.
- That is the direct route for packets to that network.
- The route to this network is configured statically on the router.
Explanation: Routing table entries that begin with the letter D are learned dynamically using the EIGRP routing protocol. Static route entries on the routing table are identified with S. Directly connected route entries are denoted by the letter C.
9. What is the purpose of classifying Cisco IP routing table entries as ultimate route, level 1 route, level 1 parent route, and level 2 child routes?
- To enable the implementation of dynamic routing protocols
- To explain the operation of the routing table as a flat database
- To enable Cisco routers to implement both IPv4 and IPv6 routing
- To explain the operation of the hierarchical structure of the routing table
Explanation: The Cisco IP routing table is not a flat database. It has a hierarchical structure that is used to expedite the lookup process when locating routes and forwarding packets. The terms ultimate route, level 1 route, level 1 parent route, and level 2 child routes describe the operation and the hierarchical nature of the routing table contents.
10. What are two functions of dynamic routing protocols? (Choose two.)
- to maintain routing tables
- to assure low router overhead
- to avoid exposing network information
- to discover the network
- to choose the path that is specified by the administrator
Explanation: Dynamic routing protocols exist to discover the network, maintain routing tables, and calculate the best path. Having low levels of routing overhead, using the path specified by the administrator, and avoiding the exposure of network information are functions of static routing.