Understanding IP Addresses: IPv4 vs IPv6

IP Addresses Explained

An IP (Internet Protocol) address is a unique numerical label assigned to every device connected to a network. Think of it as a postal address for your device — it identifies where data should be delivered on the network.

IPv4

IPv4 uses 32-bit addresses, written as four groups of numbers separated by dots (e.g., 192.168.1.1). Each group can range from 0 to 255. This format allows for approximately 4.3 billion unique addresses — which seemed more than enough when the internet was designed in 1983, but proved insufficient as billions of devices came online.

Private vs Public IPv4 Addresses

Certain IPv4 ranges are reserved for private networks and are not routable on the public internet:

• 10.0.0.0 – 10.255.255.255 (10.0.0.0/8)
• 172.16.0.0 – 172.31.255.255 (172.16.0.0/12)
• 192.168.0.0 – 192.168.255.255 (192.168.0.0/16)

Your home router uses an address in one of these ranges (usually 192.168.1.1 or 192.168.0.1) as its local IP. Your public IP — visible to websites you visit — is a different address assigned by your ISP.

IPv6

IPv6 uses 128-bit addresses written in hexadecimal (e.g., 2001:0db8:85a3:0000:0000:8a2e:0370:7334). This provides approximately 3.4 × 10^38 unique addresses — effectively unlimited. IPv6 also includes features like auto-configuration and improved security headers.

Why the Transition to IPv6 Is Slow

Despite IPv4 exhaustion (the last large blocks were allocated in 2011), IPv6 adoption is gradual because NAT (Network Address Translation) allows thousands of devices to share a single public IPv4 address. NAT is built into every home router, delaying the urgency of IPv6 adoption for most users.