Networking Basics Questions and Answers

Answer: A

Correct answer: in case of traffic overloading

Congestion occurs when the traffic offered to a link or a router exceeds what it can carry, so queues build up, delay rises and packets are eventually dropped. It is a capacity problem, not a failure: nothing has broken. TCP responds by treating loss as a congestion signal and reducing its window, which is what keeps the Internet stable under load; a terminated connection or a failed node is a quite different condition.

Answer: C

Correct answer: FCC

The Federal Communications Commission regulates interstate and international communications by radio, television, wire, satellite and cable, and it allocates the radio spectrum within the United States. The ITU-T issues international telecommunication recommendations but does not regulate commerce; the IEEE develops standards such as the 802 series; and ISOC is the parent body of the IETF.

Answer: B

Correct answer: virtual private network

A VPN carries private traffic across a public network such as the Internet by encapsulating and usually encrypting it, so remote sites and travelling users appear to be on the same private network. An enterprise private network uses the organisation’s own leased infrastructure and does not cross public networks at all; a LAN is confined to one site; and a SAN connects storage devices rather than networks.

Answer: B

Explanation: A protocol stack refers to a group of protocols that are running concurrently that are employed for the implementation of network protocol suite. Each layer in the network model has to use one specific protocol from the protocol stack.

Answer: D

Correct answer: 128 bits

An IPv6 address is 128 bits, four times the 32 bits of IPv4, and is written as eight groups of four hexadecimal digits separated by colons - for example 2001:0db8:0000:0000:0000:ff00:0042:8329, which may be shortened to 2001:db8::ff00:42:8329. The enlarged space gives about \( 3.4 \times 10^{38} \) addresses, enough that address exhaustion ceases to be a design constraint. Note the unit: 128 bits, which is 16 bytes, not 128 bytes.

Answer: C

Correct answer: G

802.11g runs in the 2.4 GHz band at up to 54 Mbps and is backward compatible with 802.11b, which is why it displaced it so quickly. 802.11a also reaches 54 Mbps but does so at 5 GHz, so it is not compatible with b or g equipment. 802.11b is limited to 11 Mbps, and 802.11n is faster than 54 Mbps and works in both bands.

Answer: B

Correct answer: protocol stack

A protocol stack is the particular set of protocols a system actually runs, one at each layer - for example Ethernet, IP, TCP and HTTP. A protocol suite is the wider family from which they are drawn, such as TCP/IP as a whole, and protocol architecture refers to the layered design itself. The stack is the concrete implementation; the suite and the architecture are the collection and the pattern.

Answer: C

Correct answer: LCP

The Link Control Protocol negotiates the characteristics of the PPP link itself: authentication with PAP or CHAP, dynamic addressing, callback, compression, error detection and multilink. NCP is the layer above it, negotiating one control protocol for each network layer protocol carried. The division is worth holding: LCP concerns the link, NCP concerns what is carried over it.

Answer: D

Correct answer: copy tftp flash

An upgrade writes a new IOS image from a TFTP server into flash, so the source is tftp and the destination flash. Reversing the two words gives copy flash tftp, which is the backup. copy tftp run and copy tftp start load configuration files rather than images, and config net merges a configuration from the network into the running one.

Answer: B

Correct answer: Medium

The transmission medium is the physical path a signal travels along - twisted pair, coaxial cable, optical fibre, or the free space used by radio. It is one of the five components of a data communication system, alongside the message, the sender, the receiver and the protocol. A route or path is the sequence of devices a message passes through, which is a logical rather than a physical notion.