Computer networks worksheet with answers

What does a VPN mainly provide?

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

In a peer-to-peer network:

1. ADevices cannot communicate directly
2. BEach node can act as both a client and a server
3. COnly routers may share files
4. DOne central server handles every request

What is the main job of a firewall?

1. ATo speed up downloads by caching files
2. BTo convert domain names into addresses
3. CTo allow or block traffic according to security rules
4. DTo assign IP addresses to hosts

Which host is in the same /16 subnet as 10.1.2.3?

1. A10.0.2.3
2. B11.1.2.3
3. C10.1.200.5
4. D10.2.2.3

TLS provides which security properties for HTTPS?

1. AAnonymity of the user
2. BProtection against all malware and phishing on the visited site
3. CConfidentiality, integrity and server authentication
4. DOnly faster loading

What does an MX record in DNS specify?

1. AAn alias name for another host
2. BThe IPv4 address of a web server
3. CThe name servers for a zone
4. DThe mail servers that accept email for a domain

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

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

Why does the side that closes a TCP connection first stay in the TIME_WAIT state for twice the maximum segment lifetime?

1. ATo wait for the DNS cache to expire
2. BSo delayed segments die out and the final ACK can be resent if it was lost
3. CTo let the routers along the path update their routing tables for the next connection
4. DTo keep the encryption keys for later reuse