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4.8 Journal: the network exists

This entry is different from the others: part of it is reference material you'll come back to for the rest of the course, so give it a little more care than usual.

Make a permanent note, not a daily one. In your vault, create Projects/lab-network.md and put in it:

  • The addressing table from lesson 4.3, edited to match what you actually built
  • Which hypervisor network is which segment, by its real name (VMnet8, VMnet2, lab-nat, whatever yours are called), and whether DHCP is on or off for each
  • Your gateway address, read from ip route rather than assumed
  • Tier 2: the firewall's addresses on both sides, and where you wrote its root password
  • Tier 3: whether you set up Tailscale, and what it can reach

Then today's daily note, four headings as usual:

Under what I did: the networks you created, Kali imported, and for Tier 2 the firewall built and both segmentation tests run.

Save the capture from lesson 4.7. Paste the Follow-TCP-Stream text of your plaintext HTTP request into the entry, under a heading you'll be able to find again. Lesson 7.6 asks you to run the same capture against your own HTTPS site and put the two side by side, and that comparison is much more convincing when the first half is your own traffic from weeks earlier rather than a screenshot from a book.

Under what broke: something in this module usually does. A VM on the wrong virtual switch, DHCP handing out an address from the range you thought you'd disabled, the firewall's interfaces assigned backwards. Write the symptom and how you worked out which of the four questions from 4.1 was unanswered. That reasoning is the actual skill.

Under what I learned: explain, in your own words, the difference between NAT and host-only, and why this course refuses to use bridged. If you can teach it to the page you'll be able to teach it in an interview.

Under open questions: "what happens to my lab's DNS when the domain controller arrives" is an excellent one, and Module 5 answers it directly.

cd ~/git/lab-journal
git add -A
git commit -m "journal: module 4, lab network built"
git push

Tick Module 4 in Projects/lab-progress.md.