If you have a prefix length of /19, what is your custom subnet mask?

If you have a prefix length of /19, what is your custom subnet mask?

• A. 255.255.192.0
• B. 255.255.224.0
• C. 255.255.240.0
• D. 255.255.248.0

Answer: (B)

A prefix length of /19 indicates that the first 19 bits of the subnet mask are set to "1," while the remaining bits are set to "0." To derive the subnet mask from this prefix length, you first convert the 19 bits into its decimal form. The binary representation of a /19 subnet mask is: ``` 11111111.11111111.11111100.00000000 ``` This represents the first two octets (255.255) fully filled with 1s, and the first three bits of the third octet are also filled with 1s. The remaining bits are 0s. To convert the binary to decimal: - The first two octets are straightforward: 255 and 255 (since 11111111 is 255). - The third octet in binary is 11111100, which equals: - 128 + 64 + 32 + 16 + 8 + 4 + 0 + 0 = 192. Hence, the third octet in decimal is 192. Putting this all together, the subnet mask for a prefix length of /19 is 255.255.192.0. Therefore, the

A prefix length of /19 indicates that the first 19 bits of the subnet mask are set to "1," while the remaining bits are set to "0." To derive the subnet mask from this prefix length, you first convert the 19 bits into its decimal form.

The binary representation of a /19 subnet mask is:

11111111.11111111.11111100.00000000

This represents the first two octets (255.255) fully filled with 1s, and the first three bits of the third octet are also filled with 1s. The remaining bits are 0s.

To convert the binary to decimal:

• The first two octets are straightforward: 255 and 255 (since 11111111 is 255).

• The third octet in binary is 11111100, which equals:

• 128 + 64 + 32 + 16 + 8 + 4 + 0 + 0 = 192.

Hence, the third octet in decimal is 192.

Putting this all together, the subnet mask for a prefix length of /19 is 255.255.192.0.

Therefore, the