Powers of two, an important skill to master.

Working on computers and networking for over a decade there is one skill set that I recommend anyone who works on computers to know. This skill set is the “Power of Two”. The powers of two is an import skill to master. Mastering this skill will help when subnetting, supernetting and writing access lists or programs.

Since computers communicate digitally it interprets data in zeros and ones. This is why knowing your powers of twos will help. For example. If you are subnetting you can use the power of two to determine how many bits to borrow for hosts and networks quickly and to find out what increments to use when subnetting or writing access lists.

Below is a list of the power of twos that are commonly used when working in a network environment. The list contains 2 to the power of which is 1 down to 2 to the power of 32 which is 4294967296.

• 2⁰    1
• 2¹    2
• 2²    4
• 2³    8
• 2⁴    16
• 2⁵    32
• 2⁶    64
• 2⁷    128
• 2⁸    256
• 2⁹    512
• 2¹⁰   1024
• 2¹¹   2048
• 2¹²   4096
• 2¹³   8192
• 2¹⁴   16384
• 2¹⁵   32768
• 2¹⁶   65536
• 2¹⁷   131072
• 2¹⁸   262144
• 2¹⁹   524288
• 2²⁰   1048576
• 2²¹   2097152
• 2²²   4194304
• 2²³   8388608
• 2²⁴   16777216
• 2²⁵   33554432
• 2²⁶   67108864
• 2²⁷   134217728
• 2²⁸   268435456
• 2²⁹   536870912
• 2³⁰   1073741824
• 2³¹   2147483648
• 2³²   4294967296

Once you have learned the powers of two. You should find it much faster and easier to get the work done with subnetting and writing access lists since you will be able to quickly identify ranges and how many bits it will take to perform the work.

You can check my previous post TCP/IP Subnetting if you need a refresher in TCP/IP subnetting.

I would like to give some credit to Todd Lammle who explained that knowing the Powers of Two in his CCNA Study Guide. He gives details instructions on how to subnet quickly and efficiently. I recommend his book and you can get it cheap on Amazon.com for a reasonable price of $40.00.

I hope that this helps many of those who may have been struggling with Binary Math and learning how to subnet.