Is the IP address 224.0.0.0 routable over the internet?
2 Answers
No. IPv4 addresses in the range 224.0.0.0/4
are not regular addresses; they are multicast addresses. Multicast is normally confined to a single LAN. Multicast routing must be enabled on all the routers between the multicast source and the multicast group subscribers for it to be able to be routed to another LAN, and that simply isn't practical on the public Internet.
There are several multicast ranges within the overall multicast address range (see IPv4 Multicast Address Space Registry), and 224.0.0.0/24
is the Local Network Control Block of addresses. Multicast packets sent to addresses in this block are not to be routed (see RFC 5771, IANA Guidelines for IPv4 Multicast Address Assignments, Section 4, Local Network Control Block).
Addresses in the Local Network Control Block are used for protocol control traffic that is not forwarded off link. Examples of this type of use include OSPFIGP All Routers (224.0.0.5) [RFC2328].
From IPv4 Multicast Address Space Registry
Extensions for IP Multicasting [RFC1112] specifies the extensions required of a host implementation of the Internet Protocol (IP) to support multicasting. The multicast addresses are in the range 224.0.0.0 through 239.255.255.255. Address assignments are listed below.
The range of addresses between 224.0.0.0 and 224.0.0.255, inclusive, is reserved for the use of routing protocols and other low-level topology discovery or maintenance protocols, such as gateway discovery and group membership reporting. Multicast routers should not forward any multicast datagram with destination addresses in this range, regardless of its TTL