James Hanback. A sensible person would not run a 5K without doing some physical conditioning to ensure you get there. You will most likely be prepared for any public race, whether you are a professional who needs to warm up and properly hydrate before the race begins or a novice who is unable to walk to their car due to exhaustion, and you will have the right equipment.
It is the same with IPv6 deployment (or any other unfamiliar technology). It is best to not attempt to deploy and manage an IPv6 network before you are confident that you understand the basics. In the previous posts, I have explained what an IPv6 Address is, how they differ from IPv4 addresses and how to notate IPv6 adress. Also, I have discussed the different uses of IPv6 addresses. We have the equipment we need to start training for IPv6 deployment.
Training for a race requires your body to use its muscles, circulatory system and heart as efficiently as possible in order to get you to the finish line. Learning about IPv6 prefixes is essential to subnet IPv6 in your organization.
Ready?
The Warm Up
Subnetting an IPv6 network may be different than subnetting one IPv4 network. However, there are some concepts you can use in IPv4 subnetting to help you prepare for your IPv6 subnetting training. Both IPv4 as well as IPv6 use the slash notation for the number of subnetwork bit in an address. The number of bits in a subnetwork address are always counted starting at the leftmost bit of the address. Because of its position in the bit order, the subnetwork address can also be called the address prefix. You can subnet each address using slash notation in IPv4 or IPv6 by simply appropriating host bit for subnetwork bits. This is also known to be moving the subnetwork boundary to the right.
You may recall that each decimal number in a dotteddecimal IPv4 address is an octet. Each octet’s leftmost bit is a decimal value 128. Each bit in an octet is worth half of the previous bit. The decimal value of an Octet can be calculated using a left to right place system. Each bit that is set at 1 represents the decimal number that was assigned to that bit’s location. The binary value of the first OCTET in the IPv4 address is 192.168.51.50. This is because the 1 in 128-bit plus the 1 64-bit equals 192. Based on this conversion method, the entire binary equivalent of the IPv4 address 192.168.51.50 becomes 11000000.10101000.00110011.00110010.
A slash notation, such as 192.168.51.50/30, indicates that the first 30 bits in an IPv4 adress are the network bits or prefix. Therefore, the subnetwork bits in the IPv4 address of 192.168.51.50/30 are 11000000.10101000.00110011.001100. The host bits are the last 2 bits of an IPv4 address. They are 1 and 0. You can convert the subnetwork bits only to dotted decimal format and you will find that the prefix (or subnetwork address) of 192.168.51.50/30 becomes 192.168.51.48.
There are only two bits left in the subnet 192.168.51.48/30, so you can conclude that there are only four possible hostbit combinations for the subnet 192.168.51.48/30: 00, 011, 10, and 11. You will no doubt recall well that the first address in an IPv4 network is always the subnetwork adress and the last address in an IPv4subnetwork is always its broadcast address. This knowledge allows you to deduce that the 01 host bits combin are the most important in calculating an assignable IPv4 range from this subnetwork.
