IPv6 mobility, known as IPv6 Mobility, is a set of protocols and features designed to allow devices to move between different networks without losing connectivity or changing their IP address.

This is particularly useful for mobile devices such as smartphones, tablets and laptops that change networks frequently due to their physical mobility.

Mobility in IPv6 improves upon existing methods in IPv4, providing a more efficient and scalable approach.

Main Characteristics of Mobility in IPv6

1. Home Address and Care-of Address (CoA):

• Home Address: It is the permanent IP address of a device within your “home network” (the network it originally belongs to).
• Care-of Address: This is the temporary IP address assigned to a device when it is on a “foreign network” (a network other than your home network).

2. Home Agent and Foreign Agent:

• HomeAgent: It is a router on the device's home network that maintains information about the device's current location and acts as an intermediary to send traffic directed at the device's Home Address to its Care-of Address.
• Foreign Agent: In IPv6, the foreign agent function is often internal, where the device itself manages its registrations with its Home Agent without the need for a specific agent on the visited network.

Operation of Mobility in IPv6

When a mobile device moves and changes networks, it automatically detects its network change and obtains a new Care-of Address from the local network.

You then inform your Home Agent about your new location by sending a location update message.

The Home Agent then directs any data destined for the device's Home Address to its new Care-of Address using a technique called “encapsulation and tunneling,” which ensures that the device can continue receiving its traffic without interruption.

Benefits of Mobility in IPv6

• Session Continuity: Allows active applications and sessions to remain continuous and uninterrupted, even when the device changes locations and networks.
• Improved Efficiency: Reduces the need to assign and manage temporary IP addresses and minimizes the administrative burden on networks.
• Native Mobility Support: IPv6 includes built-in support for mobility, eliminating the need for additional solutions and improving interoperability between devices and networks.

Considerations

• Security: Location updates and tunneling must be protected to prevent redirection or session hijacking attacks.
• Network Configuration and Support: Network infrastructure must be properly configured to support IPv6 mobility features, including configuring Home Agents and managing appropriate security policies.

In summary, IPv6 mobility facilitates more robust and efficient mobility management for devices on changing networks, taking advantage of improvements in the IPv6 protocol to provide a seamless and continuous user experience as they move between different locations and networks.