- Broadcast address
In
computer networking , a broadcast address is anIP address that allows information to be sent to all machines on a given subnet rather than a specific machine. The exact notation can vary byoperating system , but the standard is laid out in RFC 919.Generally, the broadcast address is found by taking the
bit complement of thesubnet mask and then OR-ing it bitwise with the IP address.Example: to broadcast a packet to an entire class B subnet using a
private IP address space, the broadcast address would be 172.16.255.255.This can be found from the subnet mask (255.255.0.0) and the IP address (eg. 172.16.48.196) - the complement of the subnet mask is 0.0.255.255, and 172.16.48.196 | 0.0.255.255 = 172.16.255.255.
A special type of IP address is the limited broadcast address 255.255.255.255. A broadcast involves delivering a message from one sender to many recipients. This broadcast is 'limited' in that it does not reach every node on the Internet, only nodes on the LAN.
Other Protocols
IPX
The Novell
IPX protocol allows broadcast as well. When the network address is specified as FFFFFFFF, the packet is to be sent to all the networks available. When the target node address is specified as FFFFFFFFFFFF, the packet is intended to be received by all the computers in the network.Ethernet layer
Broadcast is possible also on the underlying
data link layer .Ethernet frames can be addressed to every computer on a given LAN segment if they are addressed toMAC address FF:FF:FF:FF:FF:FF. Ethernet frames that contain IP broadcast packages are usually sent to this address. ARP typically uses segment-wide broadcast for its queries.See also
*
Default gateway
*Multicast address External links
* [http://learn-networking.com/network-design/how-a-broadcast-address-works How a Broadcast Address Works]
*RFC 919
Wikimedia Foundation. 2010.
