Networking Basics Questions and Answers

Answer: B

IEEE 802.5 token ring operates at 4 and 16 Mbps.

The token ring standard, based on IBM's design, was specified at 4 Mbps and later at 16 Mbps. Stations pass a token around the ring, and only the holder may transmit.

2, 32 and 64 Mbps are not the standard 802.5 rates (later high-speed token ring at 100 Mbps saw little use), so the other pairs are wrong.

Answer: C

The flag byte is 01111110.

Bit-oriented protocols such as HDLC and PPP mark the start and end of every frame with the flag 01111110 (hexadecimal 7E). Bit stuffing ensures this pattern never appears inside the data: the sender inserts a 0 after any five consecutive 1s.

The other patterns are not used as frame delimiters; in particular they lack the six consecutive 1s that make the flag unique.

Answer: D

The protocol is stop and wait.

In stop-and-wait, the sender transmits one frame and then waits for its acknowledgement before sending the next. It is simple but leaves the link idle while waiting, so it uses bandwidth poorly on long or fast links.

Sliding window protocols, including Go-back-N, let the sender transmit several frames before an acknowledgement arrives. Piggybacking is the technique of carrying acknowledgements on outgoing data frames, not a protocol that sends one frame at a time.

Answer: B

Correct answer: Every 2 seconds

Bridge protocol data units are sent every two seconds by default, which is the spanning tree hello time. They carry the bridge ID and path cost information from which every switch determines the root bridge, its own root port and any blocking ports. The interval matters because convergence times are derived from it: max age is twenty seconds, ten missed hellos, and forward delay fifteen.

Answer: A

Correct answer: 1

A switch breaks up collision domains, not broadcast domains: a broadcast frame arriving on one port is flooded out of all the others, so all twelve ports remain in a single broadcast domain by default. Splitting that domain requires either a router or VLANs configured on the switch, each VLAN forming a broadcast domain of its own. The complementary question - how many collision domains - gives twelve.

Answer: A

Correct answer: 1

Spanning tree elects exactly one root bridge per broadcast domain, however many switches there are, and every other switch computes its shortest path to that root. The election is by lowest bridge ID - priority first, then MAC address as the tiebreaker - which is why the priority is normally set deliberately on the switch that should win, rather than left to the accident of which switch has the lowest MAC address.

Answer: A

Explanation: A computer network, or data network, is a digital telecommunications network which allows nodes to share resources. In computer networks, computing devices exchange data with each other using connections between nodes. The nodes have certain processes which enable them to share a specific type of data using a distinct protocol.

Answer: B

Explanation: A virtual private network extends a private network across a public network, and enables users to send and receive data across shared or public networks as if their computing devices were directly connected to the private network.VPN provides enhanced security and online anonymity to users on the internet. It is also used to unblock websites which are unavailable in certain regions.

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.