CCNA Routing and Switching Portable Command Guide (ICND1 100-105, ICND2 200-105, and CCNA 200-125), 4th Edition

Chapter 1. How to Subnet

Class A–E Addresses

N = Network bitsH = Host bitsAll 0s in host portion = Network or subnetwork addressAll 1s in host portion = Broadcast addressCombination of 1s and 0s in host portion = Valid host address

Converting Between Decimal Numbers and Binary

In any given octet of an IP address, the 8 bits can be defined as follows:

To convert a decimal number into binary, you must turn on the bits (make them a 1) that would add up to that number, as follows:

187 = 10111011 = 128+32+16+8+2+1

224 = 11100000 = 128+64+32

To convert ...