An administrator is given the following network information to configure a server with a static IP address: 10.152.0.4/21
Which of the following is the subnet mask for the given IP address?
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A. B. C. D.C.
The given IP address 10.152.0.4/21 represents a Class A IP address, which has a default subnet mask of 255.0.0.0. The "/21" at the end of the IP address indicates that the first 21 bits of the subnet mask are used to identify the network portion of the IP address, leaving the remaining 11 bits for host addresses.
To determine the subnet mask, we need to convert the "/21" into a subnet mask format. We can do this by starting with a binary number consisting of 32 bits (which is the length of an IPv4 address) and setting the first 21 bits to 1 and the remaining 11 bits to 0.
Starting with the leftmost bit (the most significant bit), we have:
11111111 11111111 11111000 00000000
Converting this binary number into decimal format, we get:
255.255.248.0
Therefore, the subnet mask for the given IP address 10.152.0.4/21 is 255.255.248.0.
Option C is the correct answer.