Reserved address
255.255.255.255
255.255.255.255 is in 240.0.0.0/4, space that isn't assigned for use (RFC 1112). It isn't routed on the public internet, so there's nothing public to look up. The limited broadcast address: a packet sent to it reaches every device on the local network, and routers don't pass it on. DHCP uses it to find a server.
At a glance
- Block
- 240.0.0.0/4
- Defined in
- RFC 1112
- On the public internet
- No
About this block
In IPv4, 240.0.0.0/4 (the old Class E) has been reserved “for future use” since 1989 and was never opened up. Most operating systems and routers refuse to use it.
In IPv6, only 2000::/3 is handed out for public addresses so far. The rest of the space is unassigned or reserved.
Where you'll see it
- 255.255.255.255, the broadcast address, in DHCP and other local-network traffic.