CCENT/CCNA ICND1 100-101 Official Cert Guide

Mask Conversion Problem 8: Answer

The answer is 255.224.0.0.

For problem 8, with a prefix of /11, you start at Step 1 by writing down 11 binary 1s, as shown here:

11111111 111

At Step 2, you add binary 0s until you have 32 total bits, as shown next:

11111111 11100000 00000000 00000000

The only remaining work is to convert this 32-bit number to decimal, remembering that the conversion works with 8 bits at a time.