Computer networks worksheet with answers

What does a VPN mainly provide?

1. AAn encrypted tunnel across an untrusted network such as the internet
2. BA faster physical connection to the internet through a dedicated line
3. CA free public IP address for every device
4. DAutomatic backup of files to a server

In networking, a protocol is:

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

In which network topology is every device connected to one central switch or hub?

1. ARing
2. BStar
3. CFull mesh
4. DBus

Which medium access method did classic shared (half-duplex) Ethernet use?

1. ACSMA/CA
2. BTDMA
3. CToken passing
4. DCSMA/CD

What is the network address of the host 192.168.10.77/26?

1. A192.168.10.76
2. B192.168.10.128
3. C192.168.10.0
4. D192.168.10.64

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

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

By Shannon's theorem, what is the capacity of a 1 MHz channel with a signal-to-noise ratio of 255?

1. A255 Mbit/s
2. B1 Mbit/s
3. C2 Mbit/s
4. D8 Mbit/s

Stations A and C both reach access point B but cannot hear each other, so their frames collide at B. How does 802.11 help?

1. AOptional RTS/CTS exchanges: the AP's CTS tells all nearby stations to wait
2. BBy increasing the TTL of the frames
3. CBy making A and C use collision detection so they stop sending when frames overlap
4. DBy routing A's frames through C