Computer Internet Questions and Answers

Answer: A

Correct answer: 1 and 4

An Ethernet frame header carries the source and destination MAC addresses; network-layer addresses live in the IP header inside the frame, where Ethernet neither reads nor uses them.

Answer: B

Correct answer: Wide area network

WAN stands for Wide Area Network - a network spanning cities or countries, in contrast with the LAN's single site.

Answer: C

Correct answer: POP3

POP3 downloads messages from the server to the client, whereas SMTP is used to send mail outward. The two work together: SMTP delivers a message to the recipient’s server and POP3 or IMAP fetches it from there.

Answer: D

Correct answer: LAN

A network confined to a single site is a local area network. A MAN covers a city, DSL is an access technology and RAM is memory.

Answer: B

Correct answer: Static packet filtering is more secure than dynamic packet filtering

Static filtering judges each packet on its headers alone, with no memory of what has gone before. Stateful and dynamic filtering track connections and so can tell a legitimate reply from an unsolicited packet, which makes them the more secure of the two - so the statement claiming the reverse is the one that does not hold.

Answer: C

Correct answer: Both 1 and 2

A firewall does both: it blocks traffic that should not reach the network at all, and it applies rules deciding which of the permitted traffic may reach which internal resources.

Answer: C

Correct answer: Reliable, ordered delivery of data

TCP numbers its segments, acknowledges them and retransmits anything lost, so the receiver sees the bytes in the order sent. UDP omits all of that, which is why it is preferred for live video and voice where a late packet is worse than a missing one.

Answer: C

Correct answer: Coaxial Cable

Guided media confine the signal to a physical path: twisted pair, coaxial cable and optical fibre. Unguided media - radio, microwave, infrared - let it travel through free space.

Answer: D

Correct answer: All of the above

All three are true of a firewall: it may be implemented in hardware or in software, it examines the traffic crossing a boundary, and what it does with each packet is decided by a configured set of rules.

Answer: C

Correct answer: Compression

Compression reduces a file's size by removing or re-encoding repetition. It is lossless when the original can be restored exactly and lossy when some detail is discarded for a greater saving.