Frequently Asked Question

What is the difference between IPv4 and IPv6?

IPv4 addresses are 32 bits long, giving about 4.3 billion unique addresses, written as four decimal octets like 192.168.1.42. That space ran out around 2011 at the regional registry level, and the patches keeping IPv4 alive (NAT, CIDR, private address space) are why your laptop almost always sits behind a router that translates between a private 10.x or 192.168.x address and a single public address.

IPv6 addresses are 128 bits long, about 3.4 × 10³⁸ of them, written as eight colon-separated hex groups like 2001:db8::1. The huge space removes the need for NAT, simplifies routing, and bakes in autoconfiguration (SLAAC). Adoption is slow but steady; major mobile networks and large cloud providers are IPv6-first, and most modern operating systems run a dual stack that prefers IPv6 when both are available. On Linux, ip -6 addr shows your IPv6 addresses and ip -6 route your IPv6 routing table.