In the context of IPv6, address allocation works quite differently compared to IPv4, due to the huge number of addresses available.

It is not necessary to assign a single IPv6 address per client, as was common with IPv4. Instead, Internet service providers (ISPs) typically assign blocks of IPv6 addresses to their customers, even in residential or small business environments.

How IPv6 Assignment Works:

1. Address Blocks: With IPv6, it is common for an ISP to assign each customer a block of addresses, not just one. These blocks are known as “prefixes” and are usually large enough for multiple devices or even entire subnets.

The block size is indicated by a prefix notation, such as /48, /56, or /64, where a smaller number indicates a larger block.

2. Size of Common Blocks:

• /48 or /56: In enterprise environments or for customers with significant needs, it is common to assign a /48 or /56 prefix. A /48 prefix provides 1.2 x 10^24 addresses, and a /56 provides 4.7 x 10^16 addresses.
• / 64: For residential customers, a /64 prefix is ​​often assigned for each subnet. A single /64 prefix contains 18,446,744,073,709,551,616 unique addresses, more than enough for any home.

3. Allocation by Need: If you have 3000 clients, you don't need 3000 individual global IPv6 addresses; instead, each client could receive a /64 prefix (or even /56 for enterprise clients), allowing each of them to connect literally billions of devices.

Advantages of IPv6 Blocks:

• Scalability: The allocation of one block per client facilitates the administration and scalability of the networks.
• Flexibility: Allows customers to configure multiple subnets within their network, improving organization and security.
• Endurance: Customers can manage their own addresses within the assigned block without requiring continuous interaction with the ISP to obtain more addresses.

Considerations for Suppliers:

• Assignment Policies: ISPs must follow policies established by regional Internet registries (RIRs), such as ARIN, RIPE NCC, or APNIC, which define how IPv6 addresses should be assigned.
• Support and Training: They should provide IPv6 support and training to their customers to ensure proper transition and handling of the new addresses.

In short, your Internet Service Provider should provide you with a block of IPv6 addresses that is appropriate for the number of customers you have, rather than an individual address per customer.

This is not only more practical but also in line with modern network management best practices.