1. 5.1 Network Layerhistorical

    Network-layer overview linking the original IP, NAT, ICMP, and ARP notes.

  2. 5.2 ARPhistorical

    Historical notes on ARP, address resolution, common cases, ARP attacks, and virtual IP.

  3. 5.3 ICMPhistorical

    Historical notes on ICMP, its purpose, message types, Ping, and Traceroute.

  4. 5.4 IP Protocolhistorical

    Historical notes on the IP protocol, packet format, and IP fragmentation.

  5. 5.5 NAThistorical

    Historical notes on NAT and why private/public address translation is used.