Given an IP address and subnet mask, you can
identify the subnet address, broadcast address, and
first and last usable addresses within a subnet as
follows:
1. Write down the 32-bit address and the subnet
mask below that (174.24.4.176/26 is shown
in the following figure).
2. Draw a vertical line just after the last 1 bit in
the subnet mask.
3. Copy the portion of the IP address to the left
of the line. Place all 1s for the remaining free
spaces to the right. This is the broadcast
address for the subnet.
4. The first and last address can also be found
by placing ...0001 and ...1110, respectively, in
the remaining free spaces.
5. Copy the portion of the IP address to the left
of the line. Place all 0s for the remaining free
spaces to the right. This is the subnet number.
174.24.4.176 1010111000110000000100 10110000 Host
255.255.255.192 1111111111111111111111 11000000 Mask
174.24.4.128 1010111000110000000100 10000000 Subnet
174.24.4.191 1010111000110000000100 10111111 Broadcast