LC

Implement TCP Connection Teardown (FIN/ACK Sequence)

hard6/8

Implement TCP Sliding Window Flow Control Implement a Simple Congestion Control Algorithm

Language

Compiler

2.0s Limit 256MB

Implementation

Implement a simulation of TCP connection teardown.

Requirements:

Show the 4-way termination sequence: FIN -> ACK -> FIN -> ACK
Track state transitions for both active and passive closer
Display FIN flags with sequence numbers
Show TIME_WAIT state and explain its purpose
Demonstrate simultaneous close scenario
Show RST for abortive close
Print each segment and corresponding state changes
Explain why TIME_WAIT lasts for 2*MSL

Why This Matters

TIME_WAIT accumulation from this exact 4-way close is a well-known production incident pattern for high-throughput servers like nginx and HAProxy, which is why SO_REUSEADDR and tuning net.ipv4.tcp_tw_reuse are standard operational knobs. Understanding which side is the 'active closer' also explains real connection-reset bugs when both peers close simultaneously.

Hints

0 / 3 revealed

Validation Suite

main.c

Workspace 1.0