Computer networks worksheet with answers

In a peer-to-peer network:

1. AOnly routers may share files
2. BOne central server handles every request
3. CDevices cannot communicate directly
4. DEach node can act as both a client and a server

What does "latency" mean in networking?

1. AThe number of devices on a network
2. BThe error rate of a cable
3. CThe delay for data to travel from source to destination
4. DThe maximum amount of data per second that a link can carry

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

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

Why is UDP often preferred for live video calls?

1. AUDP encrypts data automatically
2. BUDP is required for all video
3. CLow delay matters more than retransmitting every lost packet
4. DUDP guarantees every packet arrives, so the picture never freezes

What characterises a distributed denial-of-service (DDoS) attack?

1. AMany compromised machines flood a target with traffic
2. BAn attacker reads unencrypted Wi-Fi traffic from a nearby car
3. CA virus deletes files on a single PC
4. DOne attacker guesses a user's password

Which range of TCP/UDP port numbers is reserved as "well-known" ports?

1. A49152–65535
2. B0–65535
3. C0–1023
4. D1024–49151

The count-to-infinity problem occurs in which kind of routing protocol, and what helps against it?

1. ADistance-vector; split horizon and poison reverse
2. BStatic routing; adding default routes
3. CLink-state; flooding link updates
4. DPath-vector; longer AS paths

A student runs a game server on a PC behind a home NAT router. Friends on the internet cannot connect. What is the usual fix?

1. AConfigure port forwarding on the router to the PC's private address
2. BGive the PC a different MAC address so the router can find it from outside
3. CTurn off the PC's DNS client
4. DChange the PC's subnet mask to /32