Yes, IPv6 (Internet Protocol Version 6) is a layer 3 protocol according to the OSI (Open Systems Interconnection) model.

Layer 3 protocols, also known as network protocols, are responsible for the transmission of data packets between dissimilar networks, ensuring that data sent from a device correctly reaches its destination across multiple links and networks.

Main functions of IPv6 at layer 3:

1. Addressing and Routing: IPv6 provides 128-bit addresses, offering virtually unlimited address space compared to IPv32's 4-bit addresses. This allows for a more flexible and extensive allocation of addresses, as well as facilitating routing over the Internet.
2. Packet fragmentation: In IPv6, packet fragmentation is handled differently than in IPv4. Only the sending device performs the fragmentation; Intermediate routers do not fragment packets, simplifying the routing process and improving efficiency.
3. Security: IPv6 was designed with security considerations in mind, including native support for IPsec (Internet Protocol Security) to provide data encryption and authentication at the network level.
4. Mobility: IPv6 supports mobility without the need to change the primary IP address, thanks to its advanced auto-configuration and address management capabilities.
5. Protocol simplification: Despite offering expanded functionality, IPv6 simplifies several aspects of packet processing on network devices, such as eliminating the header checksum, which reduces the computational load on routers.

IPv6, being a layer 3 protocol, plays a crucial role in creating and maintaining global networks and facilitating communication and services over the Internet.

Its robust design and advanced features make it essential for modern network infrastructure, especially with the growth of the Internet of Things (IoT) and other technological developments that require a massive and growing number of IP addresses.