Computer networks worksheet with answers

Which device forwards packets between different networks based on IP addresses?

1. AA switch
2. BA repeater
3. CA router
4. DA hub

What is the default port number for SSH?

1. A53
2. B110
3. C22
4. D23

In networking, a protocol is:

1. AA list of all devices on a network
2. BA physical cable between two devices
3. CA set of rules for the format and order of messages
4. DA program that blocks viruses

What is the purpose of the TCP three-way handshake?

1. ATo establish a connection and synchronise sequence numbers
2. BTo close a connection quickly
3. CTo find the IP address of a host before data can be sent to it
4. DTo encrypt the data

What does ARP do?

1. ARoutes packets on the internet
2. BResolves domain names
3. CAssigns IP addresses automatically to hosts when they join the local network
4. DFinds the MAC address that belongs to an IP address on the local network

Why does Wi-Fi use collision avoidance (CSMA/CA) instead of collision detection?

1. AA wireless station cannot reliably detect collisions while it is transmitting
2. BCollision detection only works on fibre cables, not on shared wireless radio channels
3. CRadio signals never collide
4. DWi-Fi only allows one device per network

A DNS cache poisoning attack aims to:

1. AMake a resolver store a false IP address for a domain
2. BOverload a server with traffic so that it stops answering queries
3. CDelete DNS servers
4. DSteal Wi-Fi passwords

Head-of-line blocking in HTTP/2 over TCP occurs because:

1. AServers cannot handle parallel requests
2. BA lost TCP segment delays all multiplexed streams until it is retransmitted
3. CHTTP/2 uses UDP
4. DEach request needs its own new TCP connection, so later requests wait in a queue