IPv4
Internet Protocol version 4
ELI5 — The Vibe Check
IPv4 is the original address format for the internet — four numbers separated by dots, like 192.168.1.1. The problem? There are only about 4 billion possible addresses and we've run out. It's like trying to give every person on Earth a unique 4-digit phone number.
Real Talk
IPv4 uses 32-bit addresses expressed as four octets in dotted-decimal notation (e.g., 192.168.0.1). It supports approximately 4.3 billion unique addresses. Address exhaustion led to techniques like NAT and eventually the development of IPv6.
Show Me The Code
# IPv4 address examples
192.168.1.1 # Private (home router)
10.0.0.1 # Private (corporate)
8.8.8.8 # Google's public DNS
127.0.0.1 # Localhost (your own machine)
When You'll Hear This
"The server has an IPv4 address of 203.0.113.5." / "We're behind NAT because IPv4 addresses are exhausted."
Related Terms
CIDR (Classless Inter-Domain Routing)
CIDR is the shorthand notation for specifying IP address ranges. '192.168.1.
IP Address
An IP address is your device's home address on the internet.
IPv6 (Internet Protocol version 6)
IPv6 is the new, massive address format for the internet. Instead of four small numbers, it's eight groups of letters and numbers separated by colons.
NAT (Network Address Translation)
NAT is how your home router lets all your devices share one public IP address. Your phone, laptop, and TV each get a private IP (192.168.x.
Subnet
A subnet is a smaller chunk of a larger network, like dividing a city into neighborhoods. All devices in a subnet can talk to each other directly.