IPv4 and IPv6 are both protocols for assigning addresses to devices on the internet. IPv6 was created because we're running out of IPv4 addresses.
IPv4: The Original Standard
IPv4 addresses look like: 192.168.1.1. They use 32 bits, allowing for about 4.3 billion unique addresses. That seemed like a lot in the 1980s, but with billions of devices online, we've nearly exhausted them.
IPv6: The Future
IPv6 addresses look like: 2001:0db8:85a3:0000:0000:8a2e:0370:7334. They use 128 bits, allowing for 340 undecillion addresses (that's 340 followed by 36 zeros). We'll never run out.
Key Differences
- Address space: IPv4 has ~4.3 billion addresses; IPv6 has 340 undecillion
- Format: IPv4 uses decimal (192.168.1.1); IPv6 uses hexadecimal (2001:db8::1)
- Security: Both protocols require correctly configured encryption and network controls
- Configuration: IPv6 supports auto-configuration; IPv4 often needs DHCP
Do You Have IPv6?
Check the top of this page to see if you have an IPv6 address. If you do, you have "dual-stack" connectivity, meaning you can use both protocols.
A VPN needs to handle every protocol your connection can use. Compare the visible IPv4 and IPv6 addresses before and after connecting, and use diagnostics recommended by your VPN provider.