4000 Router Series IP Multicast Configuration Guide

Address Description

224.0.0.14 RSVP encapsulation.

224.0.0.15 All Core-Based Tree (CBT) routers.

224.0.0.16 Designated SBM.

224.0.0.17 All SBMs.

224.0.0.18 VRRP.

• IPv6 multicast addresses:

Figure 4 IPv6 multicast address format

The following describes the fields of an IPv6 multicast address:

{ 0xFF—The most significant eight bits are 11111111. This address is an IPv6 multicast address.

{ Flags—The Flags field contains four bits.

Figure 5 Flags field format

Table 4 Flags field description

Bit Descri

tion

0 Reserved, set to 0.

• When set to 0, this address is an IPv6 multicast address without

an embedded RP address.

• When set to 1, this address is an IPv6 multicast address with an

embedded RP address. (The P and T bits must also be set to 1.)

• When set to 0, this address is an IPv6 multicast address not

based on a unicast prefix.

• When set to 1, this address is an IPv6 multicast address based on

a unicast prefix. (The T bit must also be set to 1.)

• When set to 0, this address is an IPv6 multicast address

permanently-assigned by IANA.

• When set to 1, this address is a transient, or dynamically

assigned IPv6 multicast address.

{ Scope—The Scope field contains four bits, which represent the scope of the IPv6 internetwork

for which the multicast traffic is intended.