Anycast Address; Multicast Address - Cisco 7604 Configuration Manual

Appendix E Addresses, Protocols, and Ports
Figure E-1
1111 1111
F
IPv6 nodes (hosts and routers) are required to join the following multicast groups:
•
•
IPv6 routers are required to join the following multicast groups:
•
•
•
Multicast address should not be used as source addresses in IPv6 packets.
There are no broadcast addresses in IPv6. IPv6 multicast addresses are used instead of broadcast
Note
addresses.

Anycast Address

The IPv6 anycast address is a unicast address that is assigned to more than one interface (typically
belonging to different nodes). A packet that is routed to an anycast address is routed to the nearest
interface having that address, the nearness being determined by the routing protocol in effect.
Anycast addresses are allocated from the unicast address space. An anycast address is simply a unicast
address that has been assigned to more than one interface, and the interfaces must be configured to
recognize the address as an anycast address.
Catalyst 6500 Series Switch and Cisco 7600 Series Router Firewall Services Module Configuration Guide using ASDM
OL-20748-01
IPv6 Multicast Address Format
0
4 bits 4 bits
F Flag Scope
8 bits 8 bits
The All Nodes multicast addresses:
FF01:: (interface-local)
–
FF02:: (link-local)
–
The Solicited-Node Address for each IPv6 unicast and anycast address on the node:
FF02:0:0:0:0:1:FFXX:XXXX/104, where XX:XXXX is the low-order 24-bits of the unicast or
anycast address.
Solicited-Node addresses are used in Neighbor Solicitation messages.
Note
FF01::2 (interface-local)
FF02::2 (link-local)
FF05::2 (site-local)
128 bits
Interface ID
0 if permanent
Flag =
1 if temporary
1 = node
2 = link
4 = admin
Scope =
5 = site
8 = organization
E = global
IPv6 Addresses
E-9