The 16 subnets of the 140.25.0.0/16 address block are listed in the fol 

lowing code sample. The subnets are numbered 0 through 15. The

underlined portion of each address identifies the extended network pre 

fix, while the bold digits identify the 4 bits representing the subnet

number field: 

Base Network: 10001100.00011001 .00000000.00000000 = 140.25.0.0/16

Subnet #0: 10001100.00011001.0000 0000.00000000 = 140.25.0.0/20

Subnet #1: 10001100.00011001.0001 0000.00000000 = 140.25.16.0/20

Subnet #2: 10001100.00011001.0010 0000.00000000 = 140.25.32.0/20

Subnet #3: 10001100.00011001.0011 0000.00000000 = 140.25.48.0/20

Subnet #4: 10001100.00011001.0100 0000.00000000 = 140.25.64.0/20

:

:

Subnet #13: 10001100.00011001.1101 0000.00000000 = 140.25.208.0/20

Subnet #14: 10001100.00011001.1110 0000.00000000 = 140.25.224.0/20

Subnet #15: 10001100.00011001.1111 0000.00000000 = 140.25.240.0/20 

Define the Host Addresses for Subnet #3 (140.25.48.0/20)

Figure 23 shows the host addresses that can be assigned to Subnet #3

(140.25.48.0/20). 

F I G U R E   2 3 .   H o s t   A d d re s s   f o r   S u b n e t   # 3   ( 1 4 0 . 2 5 . 4 8 . 0 / 2 0 )

Since the host number field of Subnet #3 contains 12 bits, there are

4,094 valid host addresses (212  2) in the address block. The hosts are

numbered 1 through 4,094. The valid host addresses for Subnet #3 are

listed in the following sample code. The underlined portion of each

address identifies the extended network prefix, while the bold digits

identify the 12 bit host number field: 

Subnet #3: 10001100.00011001.0011 0000.00000000 = 140.25.48.0/20

Host #1: 10001100.00011001.0011 0000.00000001 = 140.25.48.1/20

Host #2: 10001100.00011001.0011 0000.00000010 = 140.25.48.2/20

Host #3: 10001100.00011001.0011 0000.00000011 = 140.25.48.3/20

: 

: 

Host #4093: 10001100.00011001.0011 1111.11111101 = 140.25.63.253/20

Host #4094: 10001100.00011001.0011 1111.11111110 = 140.25.63.254/20 

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