Computer Networks — Questions¶

This file tracks big-picture, cross-module questions about Computer Networks. For questions specific to a single module, use that module's QUESTIONS.md instead.

How to Use This File¶

1. Write questions immediately — when something is confusing, log it here before moving on.
2. Be specific — "I don't understand TCP" is less useful than "Why does TCP use a 3-way handshake instead of 2?"
3. Update status as you find answers — partial answers count.
4. Link your answers to the module or resource where you found the explanation.
5. Add follow-up questions — good answers often raise better questions.

Status Legend¶

Question Format¶

### Q{{N}}: {{QUESTION_TITLE}}

**Asked:** {{YYYY-MM-DD}}
**Status:** 🔴 Unanswered

**Full question:**
Write the question in full. Include context about what prompted it.

**My current hypothesis:**
What do you think the answer might be, even if you're not sure?

**Answer:**
_To be filled in_

**Source:**
_Where did you find/confirm the answer?_

**Follow-up questions:**
- _Any new questions this answer raised_

Questions¶

Q001: Why does TCP use a 3-way handshake instead of a 2-way handshake?¶

Asked: 2026-06-09 Status: 🔴 Unanswered

Full question: It seems like two messages (SYN → SYN-ACK) should be enough to establish a connection. Why does TCP need a third message (ACK)? What problem does it solve?

My current hypothesis: Maybe it has something to do with both sides needing to confirm the other side's sequence number?

Answer: To be filled in — see Module 04 for a detailed explanation.

Source: To be filled in

Follow-up questions: - Is there a theoretical minimum number of messages needed to establish a reliable connection?

Q002: What are the most common real-world networking mistakes that engineers make?¶

Asked: 2026-06-09 Status: 🔴 Unanswered

Full question: I want to understand the pitfalls before I develop bad habits. What do experienced network engineers wish they'd known earlier? Specifically around subnetting, security, and troubleshooting.

My current hypothesis: Based on Module 01, I suspect the most common mistakes involve forgetting about NAT traversal issues, misconfiguring firewalls, and poor subnet planning.

Answer: To be filled in

Source: To be filled in

Follow-up questions: - How do I recognize these mistakes in production? - What does a well-architected network look like vs. one that was grown organically?

Q003: How does networking relate to security?¶

Asked: 2026-06-09 Status: 🔴 Unanswered

Full question: I keep seeing Computer Networks and [[pentesting-security]] mentioned together. Are they complementary, overlapping, or competing approaches? When do I need both vs. just one?

My current hypothesis: Networks is the foundation and security is built on top — you can't secure what you don't understand.

Answer: To be filled in

Source: To be filled in

Follow-up questions: - Is there networking content I should study before starting [[pentesting-security]]? - Which modules here are most directly useful for security work?

Add new questions above this line. Keep them numbered sequentially.

Resolved Questions Archive¶

Move fully answered questions (🟢) here to keep the active list manageable.

(none yet)

Question Stats¶