Networking Basics Questions and Answers

Answer: C

Correct answer: UDP

DHCP runs over UDP, on port 67 for the server and 68 for the client. It must, because the client has no IP address when it begins: the initial DHCPDISCOVER is a broadcast from 0.0.0.0, and TCP cannot establish a connection without addresses at both ends. IP is a network layer protocol rather than a transport one, and ARP is a layer 2 resolution protocol.

Answer: D

Correct answer: Half-duplex

Half-duplex allows each end to transmit in turn but never simultaneously, as with a walkie-talkie. Simplex permits one direction only, and full-duplex allows both ends to send at once, as an ordinary telephone call does.

Answer: A

Explanation: In communications, a protocol refers to a set of rules and regulations that allow a network of nodes to transmit and receive information. Each layer in the network model has a protocol set, for example, the transport layer has TCP and UDP protocols.

Answer: D

Explanation: In simplex transmission, data flows in single direction which in this case refers to the data flowing from the keyboard to the computer. Another example would be of the mouse where the data flows from the mouse to the computer only.

Answer: A

Correct answer: Protocols

A protocol is the agreed set of rules governing a data exchange, covering syntax, semantics and timing. Standards are the documents that record such agreements formally and give them authority, and RFCs are the particular series in which the IETF publishes them. The rules themselves are the protocol; the standard and the RFC are how the rules are written down and disseminated.

Answer: D

Correct answer: Star

In a star topology each node has its own link to a central device, so a single cable failure isolates only one node. The weakness is the centre itself, whose failure brings down the whole network.

Answer: A

Correct answer: Added

Each layer, as the data passes down the stack, prepends its own header containing the information its peer at the far end needs - the transport layer adds ports and sequence numbers, the network layer addresses, the data link layer MAC addresses and a trailing checksum. This is encapsulation. At the receiver the process runs in reverse: each layer strips its own header and passes the remainder up, which is decapsulation.

Answer: B

Correct answer: Stops an interface from sending periodic dynamic updates but not from receiving updates.

The passive-interface command suppresses outgoing routing advertisements on that interface while leaving the router willing to receive them, and the network remains advertised to the rest of the topology. It is used on interfaces facing hosts or stub segments, where advertising routes wastes bandwidth and exposes the routing domain unnecessarily. Note that in EIGRP and OSPF the effect is stronger, since suppressing hellos prevents adjacencies forming at all.

Answer: C

Correct answer: optical fiber

Optical fibre carries data as light through a glass core and offers by far the greatest bandwidth of the guided media, with speeds in the gigabits and terabits per second and very low attenuation over long distances. It is also immune to electromagnetic interference and hard to tap. Twisted pair and coaxial cable both carry electrical signals and are limited by attenuation and interference well below what fibre achieves.

Answer: A

Correct answer: RFC

The Internet Engineering Task Force publishes its standards as Requests for Comments, numbered sequentially and never revised once issued - a change means a new RFC that obsoletes the old one. The name survives from the deliberately informal beginnings of the series in 1969, though an RFC on the standards track is now a formal specification. RFC 791 defines IP, RFC 793 TCP.