There are two main IP versions:
- IPv4 (32‑bit addresses): originally sufficient, now exhausted
- IPv6 (128‑bit addresses): vast address space
To extend IPv4 life, networks use subnetting and Network Address Translation (NAT). Home LAN devices get private IPv4 addresses; the router maps these to a single public IPv4 address. IPv6 does not change physical router setup.
Routers connect LAN and WAN. To host local servers, configure port forwarding in your router’s settings. For peer-to-peer discovery, look into STUN, TURN, and ICE protocols.