Subnets·IPv6 /59
IPv6
/59
2^69

IPv6 /59 prefix

/59 means the first 59 bits are the network and 69 are left for hosts. That is 2^69 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
/59
Host bits
69
Addresses
2^69
Usable hosts
2^69
/64 networks inside
2^69
Nibble boundary
No

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 /59?

2^69, of which 2^69 can actually be handed out.

Q. How is a /59 written?

IPv6 uses no mask — you simply write /59.

Q. How many /64 networks fit in a /59?

2^69.

Q. How many host bits are there?

69. Each extra network bit halves the addresses.