Networking Basics Questions and Answers

Answer: D

Correct answer: overlay network

An overlay network is a logical network constructed on top of another, its links being paths through the underlying network rather than physical connections. Peer-to-peer file sharing systems, virtual private networks and content distribution networks are the common examples. It permits new services without any change to the infrastructure, at the cost of routing decisions made in ignorance of the real topology below.

Answer: D

Correct answer: 1 Mbps

A hub is a shared medium: every port is in the same collision domain, and the 10 Mbps is divided among everyone using it. With ten users,

and half duplex means they cannot send and receive at once either. Replacing the hub with a switch would give each host its own collision domain and the full 10 Mbps, which is precisely the difference between the two devices.

Answer: D

Correct answer: all of the mentioned

A node is any device attached to the network that participates in communication, whether it originates the data, forwards it on the way, or receives it as the final destination. The term is deliberately general - hosts, routers and switches are all nodes - and the role a given node plays changes from one message to the next.

Answer: B

Correct answer: Medium

The transmission medium is the physical path along which the signal actually travels - twisted pair, coaxial cable, optical fibre or free space. It is one of the five components of a data communication system, with the message, sender, receiver and protocol. A path or route is the logical sequence of nodes a message passes through, which is a different idea from the physical carrier itself.

Answer: A

Correct answer: NCP

PPP has two sublayers above the physical link. LCP establishes, configures and tests the connection itself, handling authentication, compression, multilink and error detection. NCP then negotiates one control protocol per network layer protocol carried - IPCP for IP, IPXCP for IPX - which is how PPP supports several protocols over one link. HDLC is a different encapsulation altogether, and ISDN is a physical service.

Answer: A

Correct answer: 192.168.168.129-190

The mask 255.255.255.192 is /26, leaving 6 host bits, so the block size is

and the subnets begin at 0, 64, 128 and 192. The address 188 falls in the 128 subnet, whose broadcast is the address before the next subnet, 191. The usable hosts are therefore 129 to 190: 128 is the network address and 191 the broadcast, and neither can be assigned to a host.

Answer: A

Correct answer: personal area network

A PAN covers the space immediately around a person, typically within about ten metres, and Bluetooth is its most familiar technology - connecting a headset, keyboard or fitness tracker to a phone or computer. A LAN spans a building or campus, a WAN a country or the world, and a VPN is a logical network tunnelled over a public one rather than a matter of physical range.

Answer: D

Correct answer: ARPANET

ARPANET, built for the United States Advanced Research Projects Agency, carried its first message in 1969 and is the direct ancestor of the Internet. It demonstrated packet switching in practice and adopted TCP/IP in 1983. NSFNET followed in 1985 as the academic backbone that eventually replaced it, and the other two names are not networks that existed.

Answer: D

Correct answer: 12

Every port on a switch is its own collision domain, which is exactly what distinguishes a switch from a hub: frames are forwarded only towards the port where the destination MAC address resides, so two conversations on different ports never collide. Twelve ports therefore give twelve collision domains, while all twelve remain in one broadcast domain unless VLANs are configured.

Answer: A

Correct answer: A

A class A address uses one octet for the network and three for hosts, giving

Class B gives \( 2^{16} - 2 = 65{,}534 \) and class C only 254. The two subtracted addresses are the network address and the broadcast address, neither of which can be assigned to a host.