INTERNET PROTOCOL ADDRESS SPACE The allocation of Internet Protocol version 6 (IPv6) address space to various uses listed here [RFC2373]. Allocation Prefix Fraction of (binary) Address Space ------------------------------- -------- ------------- Reserved 0000 0000 1/256 the "unspecified"address 0:0:0:0:0:0:0:0 [RFC1970] 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 Provider-Based Unicast Address 010 1/8 Multi-Regional (IANA) 010 10000 1/256 Europe (RIPE-NCC) 010 01000 1/256 North America (ARIN) 010 11000 1/256 Asia-Pacific (APNIC) 010 00100 1/256 IPv6 Testing Address Block 010 11111 1/256 [RFC1897] Unassigned 011 1/8 Reserved for Geographic- Based Unicast Addresses 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 Use Addresses 1111 1110 10 1/1024 link local FE80 [RFC1971] Site Local Use Addresses 1111 1110 11 1/1024 site local FE90 Multicast Addresses 1111 1111 1/256 An IPv6 multicast address is an identifier for a group of nodes. A node may belong to any number of multicast groups. Multicast addresses have the following format: | 8 | 4 | 4 | 112 bits | +------ -+----+----+---------------------------------------------+ |11111111|flgs|scop| group ID | +--------+----+----+---------------------------------------------+ 11111111 at the start of the address identifies the address as being a multicast address. +-+-+-+-+ flgs is a set of 4 flags: |0|0|0|T| +-+-+-+-+ The high-order 3 flags are reserved, and must be initialized to 0. T = 0 indicates a permanently-assigned ("well-known") multicast address, assigned by the global internet numbering authority. T = 1 indicates a non-permanently-assigned ("transient") multicast address. scop is a 4-bit multicast scope value used to limit the scope of the multicast group. The values are: 0 reserved 1 node-local scope 2 link-local scope 3 (unassigned) 4 (unassigned) 5 site-local scope 6 (unassigned) 7 (unassigned) 8 organization-local scope 9 (unassigned) A (unassigned) B (unassigned) C (unassigned) D (unassigned) E global scope F reserved group ID identifies the multicast group, either permanent or transient, within the given scope. So here we assign only the group ID part of the address (the low order 112 bits). all-nodes FFxx:0:0:0:0:0:0:1 [RFC1970] all-routers FFxx:0:0:0:0:0:0:2 [RFC1970] all-rip-routers FFxx:0:0:0:0:0:0:9 [RFC2080] all-cbt-routers FFxx:0:0:0:0:0:0:10 [Ballardie] reserved FFxx:0:0:0:0:0:1:0 [IANA] linkname FFxx:0:0:0:0:0:1:1 [Harrington] all-dhcp-agents FFxx:0:0:0:0:0:1:2 [Bound] all-dhcp-servers FFxx:0:0:0:0:0:1:3 [Bound] all-dhcp-relays FFxx:0:0:0:0:0:1:4 [Bound] solicited-nodes FFxx:0:0:0:0:1:0:0 [RFC1970] multicast address FFxx::1:0:0 to FFxx::1:FFFF:FFFF Note: The "unspecified address" the loopback address, and the IPv6 Addresses with Embedded IPv4 Addresses, are assigned out of the 0000 0000 format prefix space. REFERENCES [RFC2373] Hinden, R., and S. Deering, "IP Version 6 Addressing Architecture", RFC 2373, Nokia, Cisco systems, July 1998. [RFC1897] Hinden, R., and J. Postel, "IPv6 Testing Address Allocation", Ipsilon Networks, ISI, January 1996 [RFC1970] Narten, T., E. Nordmark, and W. Simpson, "Neighbor Discovery for IP Version 6 (IPv6)", RFC 1970, IBM, Sun Microsystems, Daydreamer, June 1996. [RFC1971] Thomson, S., and T. Narten, "IPv6 Stateless Address Autoconfiguration", Bellcore, IBM, June 1996. [RFC2080] Malkin, G., and R. Minnear, "RIPng for IPv6", RFC 2080, Xylogics, Ipsilon Networks, January 1997. [Ballardie] Tony Ballardie, , February 1997. [Harrington] Dan Harrington, , July 1996. []