Essentially, we have a total of 16 bits to work with. How we choose to organize these available 16 bits will determine the structure of our address plan for a given site. A list of these would start with:. Note that the zero compression rules of IPv6 address representation require us to drop any leading zeros. As it happens, the hexadecimal structure of an IPv6 address and its associated network prefix provides an inherent method to efficiently and neatly represent such hierarchy in the form of the nibble boundary.
A nibble boundary is the boundary that naturally occurs between any two adjacent groups of 4 bits whose value is factorable by 2 4n. Adhering to this boundary has specific consequences. You could say the dividing line is subnet requirements, but how are your skills at predicting the future? What happens if a customer grows from your definition of medium to your definition of large?
Do you re-allocate and make them re-address their network? That's a complicated project. It sounds like a potential customer relations problem.
For that matter, why is it any of your business to decide what size of networks your customers have? In general a site should be a building. Give them what they want. Let them decide their needs, rather than trying to pigeonhole them into some arbitrary class. And, yes, a house is a site. An apartment is a site. Maybe with that last recommendation you decide to put your foot down. No home user is ever going to have 65 thousand subnets! No small office is ever going to have 65 thousand subnets!
I think you're right. They'll never use 65, subnets. In the home of the future maybe entertainment systems, security systems, communications systems, appliances, environmental and power controls, and medical monitors are all on separate subnets. Maybe each member of the house has a set of all these subnets dedicated just to him or her. And these are just the services we have presently.
What about all those we cannot foresee? How many subnets the household or small office of the future needs, or whether it will ever need more than one, is not really your problem.
Waste is not the point, because with IPv6 address conservation becomes irrelevant in practical designs. This means that your VPS has a subnet with 64 bits of prefix, and 64 bits of local addresses. Yes, you normally have way more than one IPv6 address. Helpful if you separate your network into subnets.
Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Asked 8 years, 8 months ago.
An allocation of a prefix shorter then 64 bits to a node or interface is considered bad practice. The shortest subnet prefix that could theoretically be assigned to an interface or node is limited by the size of the network prefix allocated to the organization. The debate around the policy of address allocation continues to go on and as this Cisco Chalk Talk from October points out:.
Typically one finds many point-to-point links throughout the infrastructure, for example, in data centers or between routers. The number of point-to-point links can add up quickly, leading to significant use of address space. Such conflicts are discussed in draft-ietf-v6ops-addcon. In general; however, it comes down to a debate between simplification of addressing and conservation of resources.
0コメント