Internet Protocol version 4
Your servers, load balancers, firewalls, and security groups are all defined in IPv4/CIDR. Know the addressing model.
What It Defines
Defines IP addressing, packet structure, and routing for IPv4. Still the dominant addressing scheme for most internet traffic.
Canonical (Normative)
Convenient (Practical)
The canonical publication point for finalized RFCs. If a protocol is standardized as an RFC, the RFC Editor text is the normative final reference. Published by the IETF, IRTF, IAB, and independent stream.
Related Specs
ISPs and cloud providers are rolling out IPv6 dual-stack. AAAA records, IPv6 CIDR, and dual-stack routing are real concerns.
Every HTTP request your app makes rides on TCP. Understanding TCP helps with latency, timeouts, keep-alives, and connection pooling.
DNS runs over UDP. QUIC and HTTP/3 run over UDP. Media and gaming often use UDP for low-latency delivery.