CS Systems & Networking 3

Question 1

A network admin notices a host can ping IP addresses but cannot load websites by name. Which service is most likely failing?

Accepted Answer

DNS resolution

Answer

Working IP connectivity with failing name-based access points to a DNS problem.

Question 2

What condition must hold, among others, for a deadlock to occur in a system?

Accepted Answer

Circular wait among processes holding resources

Answer

Deadlock requires mutual exclusion, hold-and-wait, no preemption, and circular wait.

Question 3

Why does UDP offer lower latency than TCP for real-time video streaming?

Accepted Answer

It skips connection setup, acknowledgments, and retransmissions

Answer

UDP avoids TCP's handshake, ordering, and retransmission overhead, trading reliability for speed.

Question 4

What does a Translation Lookaside Buffer (TLB) cache?

Accepted Answer

Recent virtual-to-physical address translations

Answer

The TLB stores recent page table lookups to speed up virtual address translation.

Question 5

A subnet uses the mask 255.255.255.192. How many usable host addresses does it provide?

Accepted Answer

62

Answer

A /26 subnet has 64 addresses, minus the network and broadcast addresses, leaving 62 usable hosts.

(CS) Computer Science Practice Test