Cisco Certified Internetwork Expert (CCIE) 2025 – 400 Free Practice Questions to Pass the Exam

The correct answer includes the Authentication Header as a valid IPv6 extension header, which is crucial for providing additional security features to the IPv6 protocol. The Authentication Header is used to ensure the integrity and authenticity of the data being transmitted by providing a mechanism for authentication and allowing for data integrity verification. This is particularly important in secure communications, where it is essential to ensure that the data was not altered in transit.

In the context of IPv6, extension headers are used to provide additional functionality such as routing, fragmentation, and security. The Authentication Header specifically serves the purpose of authentication, which is why it is classified as a valid extension header.

The other options mentioned may represent terms related to networking but do not stand as valid IPv6 extension headers. Understanding the specific roles of these headers is essential for comprehending how IPv6 enhances networking capabilities, particularly in terms of security and efficient data handling.