Subnets·IPv6 /44
IPv6
/44
2^84

IPv6 /44 prefix

/44 means the first 44 bits are the network and 84 are left for hosts. That is 2^84 addresses.

Addresses are 128 bits, so nobody writes a mask — only the prefix length. A home gets a /56, a single network a /64.

Prefix
/44
Host bits
84
Addresses
2^84
Usable hosts
2^84
/64 networks inside
2^84
Nibble boundary
Yes

Prefixes either side

How to read this

  • /24 means the first 24 bits are the network; the remaining 8 hold the addresses inside it.
  • Each extra bit splits the network in two and halves the addresses.
  • Usable addresses are normally the total minus two — the network and broadcast addresses.
  • IPv6 has no broadcast, so nothing is subtracted. One network is conventionally a /64.

Frequently asked questions

Q. How many addresses are in a /44?

2^84, of which 2^84 can actually be handed out.

Q. How is a /44 written?

IPv6 uses no mask — you simply write /44.

Q. How many /64 networks fit in a /44?

2^84.

Q. How many host bits are there?

84. Each extra network bit halves the addresses.