H3C Technologies H3C WX6000 Series Access Controllers - Manual (Page 313)

28-7
Table 28-2 Class D IP address blocks and description
Address block Description
224.0.0.0 to 224.0.0.255
Reserved permanent group addresses. The IP address 224.0.0.0 is
reserved, and other IP addresses can be used by routing protocols and for
topology searching, protocol maintenance, and so on. Commonly used
permanent group addresses are listed in
Table 28-3 . A packet destined for
an address in this block will not be forwarded beyond the local subnet
regardless of the Time to Live (TTL) value in the IP header.
224.0.1.0 to 238.255.255.255
Globally scoped group addresses. This block includes two types of
designated group addresses:
z
232.0.0.0/8: SSM group addresses, and
z 233.0.0.0/8: Glop group addresses; for details, see RFC 2770.
239.0.0.0 to 239.255.255.255
Administratively scoped multicast addresses. These addresses are
considered to be locally rather than globally unique, and can be reused in
domains administered by different organizations without causing conflicts.
For details, refer to RFC 2365.
z
The membership of a group is dynamic. Hosts can join or leave multicast groups at any time.
z
“Glop” is a mechanism for assigning multicast addresses between different autonomous systems
(ASs). By filling an AS number into the middle two bytes of 233.0.0.0, you get 255 multicast
addresses for that AS.
Table 28-3 Some reserved multicast addresses
Address Description
224.0.0.1 All systems on this subnet, including hosts and routers
224.0.0.2 All multicast routers on this subnet
224.0.0.3 Unassigned
224.0.0.4 Distance Vector Multicast Routing Protocol (DVMRP) routers
224.0.0.5 Open Shortest Path First (OSPF) routers
224.0.0.6 OSPF designated routers/backup designated routers
224.0.0.7 Shared Tree (ST) routers
224.0.0.8 ST hosts
224.0.0.9 Routing Information Protocol version 2 (RIPv2) routers
224.0.0.11 Mobile agents
224.0.0.12 Dynamic Host Configuration Protocol (DHCP) server/relay agent
224.0.0.13 All Protocol Independent Multicast (PIM) routers
224.0.0.14 Resource Reservation Protocol (RSVP) encapsulation
224.0.0.15 All Core-Based Tree (CBT) routers
224.0.0.16 Designated Subnetwork Bandwidth Management (SBM)
224.0.0.17 All SBMs