312-38 Exam Questions & Answers

Correct Answer: A

Correct Answer: B

A repeater is an electronic device that receives a signal and retransmits it at a higher level and/or higher power, or onto the other side of an obstruction, so that the signal can cover longer distances. A repeater is a device that receives a digital signal on an electromagnetic or optical transmission medium and regenerates the signal along the next leg of the medium. In electromagnetic media, repeaters overcome the attenuation caused by free-space electromagnetic-field divergence or cable loss. A series of repeaters make possible the extension of a signal over a distance. Repeaters remove the unwanted noise in an incoming signal. Unlike an analog signal, the original digital signal, even if weak or distorted, can be clearly perceived and restored. With analog transmission, signals are restrengthened with amplifiers which unfortunately also amplify noise as well as information. An example of a wireless repeater is shown in the figure below:

Answer option D is incorrect. A transceiver is a device that has both a transmitter and a receiver in a single package.

Answer option A is incorrect. A gateway is a network interconnectivity device that translates different communication protocols and is used to connect dissimilar network technologies. It provides greater functionality than a router or bridge

because a gateway functions both as a translator and a router. Gateways are slower than bridges and routers. A gateway is an application layer device. Answer option C is incorrect. A network adapter is used to interface a computer to a

network. "Device driver" is a piece of software through which Windows and other operating systems support both wired and wireless network adapters. Network drivers allow application software to communicate with the adapter hardware.

Network device drivers are often installed automatically when adapter hardware is first powered on.

Correct Answer: DC

Following are the two distance-vector routing protocols:

RIP: RIP is a dynamic routing protocol used in local and wide area networks. As such, it is classified as an interior gateway protocol (IGP). It uses the distance-vector routing algorithm. It employs the hop count as a routing metric. RIP

prevents routing loops by implementing a limit on the number of hops allowed in a path from the source to a destination. It implements the split horizon, route poisoning, and hold-down mechanisms to prevent incorrect routing information from

being propagated.

IGRP: Interior Gateway Routing Protocol (IGRP) is a Cisco proprietary distance vector Interior Gateway Protocol (IGP). It is used by Cisco routers to exchange routing data within an autonomous system (AS). This is a classful routing protocol

and does not support variable length subnet masks (VLSM). IGRP supports multiple metrics for each route, including bandwidth, delay, load, MTU, and reliability.

Answer options B and A are incorrect. OSPF and IS-IS are link state routing protocols.