broadcast address
broadcast address
An address that enables transmission to every node in a local network. The address is the highest numeric value of the address format being used. An Ethernet broadcast address is all binary 1's. An IP broadcast address is the highest number in its class; for example, the broadcast address of a Class C 192.168.16.0 network is 192.168.16.255.Subnet Broadcast Addresses
The broadcast address for a subnet must account for the part of the address that is reserved for the subnet. Using the above Class C example configured for six subnets would have a broadcast address of 192.168.16.31. It is derived as follows. For more on the Class C example, see subnet mask. See broadcast and multicast.
Class C Mask for Six Subnets 255 255 255 224 11111111.11111111.11111111.11100000 Step 1Invert the mask.0 0 0 31 00000000.00000000.00000000.00011111 Step 2OR the inverted mask with an IPaddress in the subnet, such as192.168.16.1. 192 168 16 1 11000000.10101000.00010000.00000001 00000000.00000000.00000000.00011111 ----------------------------------- 11000000.10101000.00010000.00011111 192 168 16 31