The broadcast address for Subnet #3 is the all 1s host address or: 

10001100.00011001.0011 1111.11111111 = 140.25.63.255 

The broadcast address for Subnet #3 is exactly one less than the base

address for Subnet #4 (140.25.64.0). 

Define the Sub Subnets for Subnet #14 (140.25.224.0/20)

After the base network address is divided into 16 subnets, Subnet #14

is subdivided into 16 equally sized address blocks. This division is illus 

trated in Figure 24. 

F I G U R E   2 4 .   S u b   S u b n e t s   f o r   S u b n e t   # 1 4   ( 1 4 0 . 2 5 . 2 2 4 . 0 / 2 0 )

Since 16 = 24, four more bits are required to identify each of the 16

subnets. This means that the organization will need to use a /24 as the

extended network prefix length. The 16 subnets of the 140.25.224.0/20

address block are listed in the following sample code. The subnets are

numbered 0 through 15. The underlined portion of each sub subnet

address identifies the extended network prefix, while the bold digits

identify the 4 bits representing the sub subnet number field: 

Subnet #14: 10001100.00011001.1110 0000.00000000 = 140.25.224.0/20

Subnet #14 0: 10001100.00011001.1110 0000 .00000000 = 140.25.224.0/24

Subnet #14 1: 10001100.00011001.1110 0001 .00000000 = 140.25.225.0/24

Subnet #14 2: 10001100.00011001.1110 0010 .00000000 = 140.25.226.0/24

Subnet #14 3: 10001100.00011001.1110 0011 .00000000 = 140.25.227.0/24

Subnet #14 4: 10001100.00011001.1110 0100 .00000000 = 140.25.228.0/24

.

.

Subnet #14 14: 10001100.00011001.1110 1110 .00000000 = 140.25.238.0/24

Subnet #14 15: 10001100.00011001.1110 1111 .00000000 = 140.25.239.0/24 

U N D E R S TA N D I N G   I P   A D D R E S S I N G

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