Multicast IP addresses
Multicast uses the Class D address space. The 224.0.0.0 to 239.255.255.255 IP address range is reserved for multicast groups. The multicast address range applies to multicast groups, not to the originators of multicast packets. The following table lists the reserved multicast address ranges and describes what they are reserved for:
Reserved Multicast address ranges
| Reserved
Address Range |
Use Notes |
|
|
224.0.0.0 to |
Used for network protocols on local net- |
In this range, packets are not forwarded |
| 224.0.0.255 | works. For more information, see RFC | by the router but remain on the local net- |
| 1700. | work. They have a Time to Live (TTL) of | |
| 1. These addresses are used for com- | ||
| municating routing information. | ||
|
Global addresses used for multicasting |
Some of these addresses are reserved, |
|
| 224.0.1.0 to | data between organizations and across |
for example, 224.0.1.1 is used for Net- |
| 238.255.255.255 | the Internet. For more information, see |
work Time Protocol (NTP). |
| RFC 1700. | ||
|
239.0.0.0 to |
Limited scope addresses used for local |
Routers are configured with filters to pre- |
| 239.255.255.255 | groups and organizations. For more | vent multicasts to these addresses from |
| information, see RFC 2365. | leaving the local system. | |
Creating multicast security policies requires multicast firewall addresses. You can add multicast firewall addresses by going to Firewall Objects > Address > Addresses and selecting Create New > Multicast Address. The factory default configuration includes multicast addresses for Bonjour (224.0.0.251-224.0.0.251, EIGRP (224.0.0.10-224.0.0.100), OSPF (224.0.0.5-224.0.0.60), all_hosts (224.0.0.1-224.0.0.1), and all_routers (224.0.0.2-224.0.0.2).