 | Copyright © 2009, Juniper Networks, Inc. All rights reserved. Trademark Notice. | |
Unicast addresses identify a single interface. Each unicast address consists of n bits for the prefix, and 128 – n bits for the interface ID.
Multicast addresses identify a set of interfaces. Each multicast address consists of the first 8 bits of all 1s, a 4-bit flags field, a 4-bit scope field, and a 112-bit group ID:
11111111 | flgs | scop | group ID
The first octet of 1s identifies the address as a multicast address. The flags field identifies whether the multicast address is a well-known address or a transient multicast address. The scope field identifies the scope of the multicast address. The 112-bit group ID identifies the multicast group.
Similar to multicast addresses, anycast addresses identify a set of interfaces. However, packets are sent to only one of the interfaces, not to all interfaces. Anycast addresses are allocated from the normal unicast address space and cannot be distinguished from a unicast address in format. Therefore, each member of an anycast group must be configured to recognize certain addresses as anycast addresses.
| Copyright © 2009, Juniper Networks, Inc. All rights reserved. Trademark Notice. | |