The most common way to configure IPv6 unicast addresses on interfaces is through Stateless Address Autoconfiguration (SLAAC).

In this method, the device automatically generates its own unicast address using the network prefix it receives in Router Advertisements (RA) and an interface identifier that is generally derived from the MAC address of the interface.

This process requires no manual intervention and is suitable for most network environments where manual configuration would be impractical due to the number of devices.

2. DHCPv6

Similar to IPv4, IPv6 also supports the configuration of IP addresses through DHCP (DHCPv6). This can be:

• Stateful DHCPv6: The DHCPv6 server assigns IP addresses and other configuration information (such as DNS) to clients. This allows centralized management of IP addresses and is useful in large networks where tracking and controlled assignment of addresses is crucial.
• Stateless DHCPv6: In this case, DHCPv6 only provides additional information (such as DNS servers) and not IP addresses. IP addresses are generated by SLAAC.

3. Manual Configuration (Static)

IPv6 addresses can also be manually configured on network interfaces. This is done by explicitly specifying the full IPv6 address in the device interface configuration.

Manual configuration is useful in environments where strict control over IP addresses is needed, such as on servers, critical network devices, or for diagnostic and testing purposes.

4. Temporary Configuration

IPv6 also allows you to assign temporary addresses that can be used for specific processes or connections. These are dynamically generated and can be designed to increase user privacy by changing regularly.

How to configure

On devices such as routers or switches that run systems such as MikroTik RouterOS, Cisco IOS, or similar, IPv6 address configuration can be done through the command line interface (CLI), graphical interfaces (GUI), or through scripts and automation for larger environments.

Considerations

• Security: When configuring IPv6 addresses, it is important to consider security aspects such as firewall and access policies to ensure that interfaces are not exposed to unwanted access.
• Compatibility: Make sure all parts of the network support IPv6, from routers and switches to end systems.

In summary, unicast addresses in IPv6 can be configured automatically, dynamically, or manually, depending on network needs and policy, and must be assigned to specific interfaces to allow effective communication within the network and to other networks.