Motivation Address Space Address Notation Address Scope Address Types Unicast Addresses Anycast Addresses Multicast Addresses Resources About Me Compression ToolAddress Types
The specific type of IPng address is indicated by the leading bits in the address.
The variable-length field comprising these leading bits is called the Format Prefix (FP).
The initial allocation of these prefixes is as follows:
| Allocation | Prefix(binary) | Fraction of Address |
|---|---|---|
| --------------------------------------------- | --------------------- | ----------------------------- |
| Reserved | 0000 0000 | 1/256 |
| Unassigned | 0000 0001 | 1/256 |
| Reserved for NSAP Allocation | 0000 001 | 1/128 |
| Reserved for IPX Allocation | 0000 010 | 1/128 |
| Unassigned | 0000 011 | 1/128 |
| Unassigned | 0000 1 | 1/32 |
| Unassigned | 0001 | 1/16 |
| Unassigned | 001 | 1/8 |
| Unassigned | 010 | 1/8 |
| Unassigned | 011 | 1/8 |
| Unassigned | 100 | 1/8 |
| Unassigned | 101 | 1/8 |
| Unassigned | 110 | 1/8 |
| Unassigned | 1110 | 1/16 |
| Unassigned | 1111 0 | 1/32 |
| Unassigned | 1111 10 | 1/64 |
| Unassigned | 1111 110 | 1/128 |
| Unassigned | 1111 1110 0 | 1/512 |
| Link-Local Unicast Addresses | 1111 1110 10 | 1/1024 |
| Site-Local Unicast Addresses | 1111 1110 11 | 1/1024 |
| Multicast Addresses | 1111 1111 | 1/256 |