HTTPfy

IPv6 /32 prefix

A /32 leaves 96 bits for subnets and hosts: 79,228,162,514,264,337,593,543,950,336 addresses, or 4,294,967,296 /64 subnets.

IPv6 /32 at a glance

Mask
ffff:ffff::
Mask (expanded)
ffff:ffff:0000:0000:0000:0000:0000:0000
Host bits
96
Addresses
79,228,162,514,264,337,593,543,950,336
Nibble-aligned
Yes, the boundary falls on a hex digit
Reverse DNS zone
8.b.d.0.1.0.0.2.ip6.arpa

Typical uses of a /32

A /32 is the classic minimum allocation a regional registry makes to an ISP or LIR. The documentation prefix 2001:db8::/32 (RFC 3849) is a /32, which is why examples throughout this site and the RFCs use it.

Example: 2001:db8::/32

First address
2001:db8::
Last address
2001:db8:ffff:ffff:ffff:ffff:ffff:ffff
Last (expanded)
2001:0db8:ffff:ffff:ffff:ffff:ffff:ffff
Next /32
2001:db9::/32

Uses the documentation prefix 2001:db8::/32 (RFC 3849). IPv6 has no broadcast address, so every address in the range is assignable, except where a platform reserves some.

Find the /32 for an address

What a /32 contains

Smaller prefixHow many
/4865,536
/5616,777,216
/60268,435,456
/644,294,967,296
/1121,208,925,819,614,629,174,706,176
/12739,614,081,257,132,168,796,771,975,168
/12879,228,162,514,264,337,593,543,950,336

Cloud support for /32

PlatformIPv6 subnet size/32?
AWS VPC/44 to /64 in steps of /4No
Azure VNetexactly /64No
Google Cloud VPC/64 (from the VPC's /48)No