IPv6
/33
2^95
IPv6 /33 prefix
/33 means the first 33 bits are the network and 95 are left for hosts. That is 2^95 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
- /33
- Host bits
- 95
- Addresses
- 2^95
- Usable hosts
- 2^95
- /64 networks inside
- 2^95
- 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 /33?
2^95, of which 2^95 can actually be handed out.
Q. How is a /33 written?
IPv6 uses no mask — you simply write /33.
Q. How many /64 networks fit in a /33?
2^95.
Q. How many host bits are there?
95. Each extra network bit halves the addresses.