Explain the complete network journey
See this course’s project requirements
A labeled network model, packet journey, transport comparison, transfer calculation and evidence-based failure explanations.
Keep your working files in your own notebook or software. Save a private description, checklist, and work link in My Proof.
What to include
- Labeled two-subnet network model.
- Name/address/gateway explanation.
- Packet and hop-limit trace.
- Transport comparison and unit-checked delay calculation.
- Two failure-card interpretations with limits.
Review and revise
Use these criteria to check your work and choose what to improve.
- Device roles and paths are correct.
- Addresses and prefixes are used consistently.
- Calculations use stated units and assumptions.
- Evidence supports the conclusions without live-system claims.
Want more background?
The idea in everyday life
Follow a fictional library request through two small networks using supplied evidence only.
A network explanation follows evidence through names, routes, transport and application behavior.
Explain the complete network journey — guided practice
Use a supplied evidence card to identify which stage is known and which remains uncertain.
Use network-notes.md or paper. All addresses and outputs are fictional. Room A has laptop A at 192.0.2.10/24, printer P at 192.0.2.20/24 and a switch. Router R has A-side 192.0.2.1/24 and B-side 198.51.100.1/24. Room B has server S at 198.51.100.20/24 and its switch. A uses default gateway 192.0.2.1. A supplied DNS record maps catalog.example to 198.51.100.20. For this /24 exercise, matching first three octets means same subnet. No live network access, capture, scanning or device configuration is needed.
1. Trace success
Write name lookup -> destination address -> local/remote decision -> gateway -> server -> application response.
You should see: The journey names six distinct stages.
Separating stages makes evidence interpretable.
2. Read failure card A
DNS lookup fails; a supplied direct-address application test succeeds.
You should see: Name resolution is a supported area to investigate.
A working address path narrows the failure without proving a root cause.
3. Read failure card B
DNS returns the expected address; the application returns HTTP 503.
You should see: The name resolved and an HTTP response returned; the service reports unavailable.
A service response is different evidence from a failed name lookup.
4. Hand off
Submit the labeled network, packet trace, transport comparison, delay calculation and two failure interpretations.
You should see: Each conclusion cites its supporting card and avoids unsupported certainty.
This is network reasoning from supplied evidence, not authorization to change a live network.
What to finish
A complete network-model packet with explicit evidence limits.
Watch for this
Treating one observation as proof of every network component’s health.
How can I tell I understand it?
Complete the changed case, explain your result, and pass the three application checks.
Quick knowledge check
Answer all 3 questions. Get at least 2 right and the lesson completes automatically.
You’ll get an explanation for each answer. Signed in? Your results save to your account.
Pass the check. We’ll save the progress.
Answer all 3 questions above and get at least 2 right. You can review the explanations and try again.
Go to the knowledge checkOptional course overview video · same video as Lesson 1
Computer Networks: Crash Course Computer Science #28
From CrashCourse. Watch here or open it on YouTube .
Optional course overview. Follow the written steps below at your own pace.Tools, templates, and lesson sources
Tools and templates
Tools open in a new tab so you can keep your place here.
Sources and further reading
Explore the references behind this lesson.
Source & access notes · checked 2026-09-12
Opened and inspected on 2026-09-12: Layers, packets, forwarding and capacity.
Access: Free public web page; no paid enrollment required.
Reuse: BY-NC-ND with additional electronic-use terms; link only, no copied diagrams or adapted book text.
Source & access notes · checked 2026-09-12
Opened and inspected on 2026-09-12: Interfaces and IP delivery.
Access: Free public web page; no paid enrollment required.
Reuse: Same textbook terms; independent exercises only.
Source & access notes · checked 2026-09-12
Opened and inspected on 2026-09-12: DNS, ARP and DHCP roles.
Access: Free public web page; no paid enrollment required.
Reuse: Same textbook terms; independent exercises only.
Report a problem with this lesson
Tell us what went wrong. Please leave out personal information and private project contents.