IPv6laajennusotsikot

IPv6laajennusotsikot, or IPv6 extension headers, are optional headers in the IPv6 protocol that provide additional functionality beyond the basic IPv6 header. These headers are used to carry metadata that is not part of the main IPv6 header, allowing for more flexible and efficient data transmission. Each extension header is identified by a specific Next Header value, which indicates the type of header that follows. The most common types of IPv6 extension headers include:

1. Hop-by-Hop Options Header: Carries optional information that must be examined by every node along the path of the packet.

2. Routing Header: Specifies a list of nodes that the packet must visit on its way to the destination.

3. Fragment Header: Used to fragment and reassemble packets that are too large to be sent as a single unit.

4. Destination Options Header: Carries optional information that is examined only by the final destination of the packet.

5. Authentication Header (AH): Provides data integrity and authentication for IPv6 packets.

6. Encapsulating Security Payload (ESP) Header: Provides confidentiality, data integrity, and authentication for IPv6 packets.

Extension headers are placed between the IPv6 header and the upper-layer header (e.g., TCP, UDP) and can be chained together, with each header indicating the type of the next header. This flexibility allows IPv6 to support a wide range of advanced networking features and security mechanisms.