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Module Quiz

Complete this quiz after finishing all concept and practice pages. Save your answers before opening separate quiz calibration.

Current Module Questions​

Question 1: Layered Model​

Name the five layers of the Internet stack in order from bottom to top, and give one representative protocol for each.

Question 2: Encapsulation​

A server receives an Ethernet frame containing an IP packet containing a TCP segment containing an HTTP request. In what order does the kernel strip headers as the data moves up the stack?

Question 3: Addressing​

Why is a MAC address not used to deliver a packet between two hosts in different cities, even though both machines have MAC addresses?

Question 4: Subnet Math​

Given 10.0.24.53/20, name the network address, the broadcast address, and the number of usable host addresses. Is 10.0.33.10 in this subnet?

Question 5: Routing​

Two routes 10.0.0.0/8 via R1 and 10.0.24.0/20 via R2 both match destination 10.0.24.53. Which is selected, and why?

Question 6: UDP Use Cases​

Why does DNS use UDP for a typical query instead of TCP?

Question 7: TCP Mechanisms​

Distinguish flow control from congestion control in TCP. Which one protects the receiver, and which one protects the network?

Question 8: TCP Lifecycle -- SYN to Established​

Walk through the exact packet flags on the wire for opening a TCP connection, from client CLOSED to both sides ESTABLISHED.

Question 9: TCP Lifecycle -- Close​

Walk through the close of that same connection, assuming the client initiates the close. Name each state and explain the purpose of TIME_WAIT.

Question 10: HTTP Methods and Status Codes​

Why is PUT /resource/42 generally retry-safe while POST /resource is not?

Question 11: HTTP/2 vs HTTP/1.1​

What specific problem does HTTP/2 multiplexing solve that HTTP/1.1 pipelining could not?

Question 12: TLS​

Why is a TLS server's certificate public information, while a TLS server's private key must never leave the server?

Question 13: Sockets API​

In the TCP server flow socket -> bind -> listen -> accept, why do you need a separate file descriptor returned by accept rather than using the listening socket for data?

Question 14: Server Architecture​

A service handles 100 concurrent clients fine on a thread-per-connection model and collapses at 10,000. Name the likely cause and the architectural fix.

Question 15: Debugging​

You capture a TCP handshake and see SYN leave the client but no SYN-ACK return. Name two plausible causes and say how you would tell them apart.

Interleaved Review Questions​

Prior Module Question 1 (from Module 3 -- Concurrency)​

Why do multiple threads sharing memory need a synchronization primitive like a mutex, and what does a mutex actually prevent?

Prior Module Question 2 (from Module 1 -- Processes)​

What does a blocking system call do to the calling process, and why is that relevant when you call accept in a single-threaded server?

Prior Module Question 3 (from Module 4 -- File Systems & I/O)​

A socket is a file descriptor. Name two syscalls that work on both regular-file fds and socket fds, and one place where the semantics differ.

Prior Module Question 4 (from Module 2 -- Memory / Virtual Memory)​

Why does an event-driven server typically use much less memory per connection than a thread-per-connection server?

Prior Module Question 5 (from Semester 1 -- Probability)​

Why is the expected number of retransmissions in a session a useful quantity, and what distribution describes it under independent packet loss?

Self-Assessment and Remediation​

Mastery Level (90-100% correct):

  • Retrieval is strong; complete all module and semester evidence gates before advancing.

Proficient Level (75-89% correct):

  • Review only the missed concept pages and redo two problems of each missed type.

Developing Level (60-74% correct):

  • Rework Practice pages 2 and 3 and revisit the TCP cluster.

Insufficient Level (<60% correct):

  • Return to the concept sequence from Cluster 1 and rebuild the layered-model habits before advancing.

Progression boundary​

Quiz performance calibrates retrieval and reasoning. It does not replace runnable work, changed-case transfer, the module assessment or required semester evidence. Consult practice calibration for the additional independent cases.