Computer networks worksheet with answers

What is the name of the data unit at the data link layer?

1. ASegment
2. BPacket
3. CMessage
4. DFrame

Which device simply repeats every incoming signal out of all its other ports?

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

What does LAN stand for?

1. ALinked application node
2. BLogical address number
3. CLocal area network
4. DLarge access network

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

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

What is a cyclic redundancy check (CRC) used for in Ethernet frames?

1. ACorrecting every bit error automatically
2. BChoosing the best route
3. CEncrypting the frame
4. DDetecting transmission errors

At which OSI layer does a switch normally operate?

1. ANetwork (layer 3)
2. BData link (layer 2)
3. CPhysical (layer 1)
4. DTransport (layer 4)

Why does IPv6 not need NAT for address shortage?

1. AIPv6 does not use addresses
2. BIPv6 only works on local networks, so addresses never need to be shared globally
3. CIts 128-bit address space is large enough to give every device a global address
4. DIPv6 encrypts all addresses

Why does TCP choose an unpredictable initial sequence number for each connection?

1. ATo encrypt the payload of each segment
2. BTo compress the data more efficiently
3. CTo select the best route to the destination for the segments of that connection
4. DTo avoid confusion with old segments and make spoofed segments harder to inject