What's Next — From ARP to IP

You've just built the foundation of your entire network stack — a real Ethernet and ARP layer that listens, understands, and talks back.

Your stack can now join a LAN, announce its presence, and resolve addresses — the essential groundwork of all Internet communication.

But at this point, you're still only handling local traffic.

The next step is to move from "Who's on my network?" to "How do I talk to them?" — in other words, from link-layer frames to network-layer packets.

Coming next: Module 3 — Speaking in Packets (IPv4 Header Parsing)

In the next module, we'll climb to Layer 3, where data starts getting direction.

You'll learn how an IP packet is structured and how routers and hosts use that information to move data across networks.

You'll:

• Decode IPv4 headers field by field (source, destination, TTL, checksum).
• Understand how each byte helps control routing and delivery.
• Safely parse real packets captured from your TAP interface.
• Write code to compute and verify the IP header checksum manually.

By the end of Module 3, your stack will no longer just see frames — it will understand packets, the universal currency of the Internet.

Congratulations on completing Module 2! Your stack now has eyes and a voice on the network. Time to give it a brain that understands IP addressing.