Subnets·IPv6 /116
IPv6
/116
4,096

IPv6 /116 prefix

/116 means the first 116 bits are the network and 12 are left for hosts. That is 4,096 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
/116
Host bits
12
Addresses
4,096
Usable hosts
4,096
/64 networks inside
None
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 /116?

4,096, of which 4,096 can actually be handed out.

Q. How is a /116 written?

IPv6 uses no mask — you simply write /116.

Q. How many /64 networks fit in a /116?

None — it is narrower than a /64.

Q. How many host bits are there?

12. Each extra network bit halves the addresses.