WGU C480 Networks Exam with Complete Solutions

Administrative distance (AD) - ANSWER-A routing protocol's index of believability. Routing protocols with a smaller AD are considered more believable than routing protocols with a higher AD. ARP command - ANSWER-Can be used in either the Microsoft Windows or the UNIX environment to see what a Layer 2 MAC address corresponds to in a Layer 3 IP address. Border Gateway Protocol (BGP) - ANSWER-BGP is a path-vector routing protocol, meaning that it can use as its metric the number of autonomous system hops that must be transited to reach a destination network, as opposed to the number of required router hops. Default static route - ANSWER-A default static route is an administratively configured entry in a router's routing table that specifies where traffic for all unknown networks should be sent. Distance vector - ANSWER-A category of routing protocol that sends a full copy of its routing table to its directly attached neighbors. Dynamic NAT (DNAT) - ANSWER-A variant of NAT in which inside local addresses are automatically assigned an inside global address from a pool of available addresses. Enhanced Interior Gateway Routing Protocol (EIGRP) - ANSWER-A Cisco proprietary protocol. Like OSPF, EIGRP is an IGP with very fast convergence and high scalability. EIGRP is considered to be an advanced distance vector or a hybrid routing protocol. Exterior Gateway Protocol (EGP) - ANSWER-A routing protocol that operates between autonomous systems, which are networks under different administrative control. Border Gateway Protocol (BGP) is the only EGP in widespread use today. Hold-down timers - ANSWER-Can speed the convergence process of a routing protocol. After a router makes a change to a route entry, the hold-down timer prevents subsequent updates for a specified period of time. This approach can help stop flapping routes from preventing convergence Interior Gateway Protocol (IGP) - ANSWER-A routing protocol that operates within an autonomous system, which is a network under a single administrative control. OSPF and EIGRP are popular examples of IGPs. Intermediate System-to-Intermediate System (IS-IS) - ANSWER-A link-state routing protocol similar in its operation to OSPF. IS-IS uses a configurable, yet dimensionless, metric associated with an interface and runs Dijkstra's shortest path first algorithm. Although using IS-IS as an IGP offers the scalability, fast convergence, and vendor-interoperability benefits of OSPF, it has not been deployed as widely as OSPF. Internet Group Management Protocol (IGMP) - ANSWER-A multicast protocol used between clients and routers to let routers know which of their interfaces has a multicast receiver attached. Link-state - ANSWER-A category of routing protocol that maintains a topology of a network and uses an algorithm to determine the shortest path to a destination network. Link-state advertisement (LSA) - ANSWER-Sent by routers in a network to advertise the networks the routers know how to reach. Routers use those LSAs to construct a topological map of a network. The algorithm run against this topological map is Dijkstra's shortest path first algorithm. Metric - ANSWER-A value assigned to a route. Lower metrics are preferred over higher metrics. Network Address Translation (NAT) - ANSWER-Allows private IP addresses (as defined in RFC 1918) to be translated into Internet-routable IP addresses (public IP addresses). Next-hop - ANSWER-An IP address on the next router to which traffic should be forwarded. Open Shortest Path First (OSPF) - ANSWER-A link-state routing protocol that uses a metric of cost, which is based on the link speed between two routers. OSPF is a popular IGP because of its scalability, fast convergence, and vendor interoperability. Poison reverse - ANSWER-This feature of a distance-vector routing protocol causes a route received on one interface to be advertised back out of that same interface with a metric considered to be infinite. Port Address Translation (PAT) - ANSWER-A variant of NAT in which multiple inside local IP addresses share a single inside global IP address. PAT can distinguish between different flows based on port numbers.