Multicast address
224.0.0.0/4
224.0.0.0/4 is the multicast block (RFC 5771). It isn't routed on the public internet, so there's nothing public to look up.
At a glance
- Block
- 224.0.0.0/4
- Defined in
- RFC 5771
- On the public internet
- No
About this block
A multicast address names a group, not a device: one packet sent to it reaches every receiver that has joined. IPv4 multicast is 224.0.0.0/4, and IPv6's is ff00::/8.
Where you'll see it
- Local network discovery: mDNS (Bonjour) at 224.0.0.251 and ff02::fb, and SSDP/UPnP at 239.255.255.250.
- IPTV and other streams that ISPs send to many homes at once.