IPV6 extended packet header

The IPV6 extended packet header is followed by the eight basic fields of the IPv6 packet header, which is the extended header and data part. The extension header is not fixed. If it exists, the extension header and data are followed by eight basic fields. The extended header part is not fixed. If it exists, it is attached in 64 bits. Multiple extended packet header layers are nested. The internal extension header is indicated by the next header field in the outer extension header. If the packet carries upper-layer data, the last header field is used to indicate the transport layer protocol, such as TCP or UDP. If no upper-layer data is carried, that is, there is no next header, the value of the next header is 59. The Code is as follows: l Hop-by-Hop option: the code is 0. It is used to carry optional information. All routers on the path through which the data packet passes must process this optional information. The structure of optional information includes three parts: optional data type, optional data length, and optional data. RFC2460 appendix B describes how to define an optional data structure. L Destination option extension header: the code is 60. It carries optional information that only needs to be processed by the destination node of the data packet. The structure of optional information includes three parts: optional data type, optional data length, and optional data. L Routing extension header: the code is 43. Defines the source route. The data section in the extension header lists the node addresses that must pass through a series of data packets to their destination. L Fragment extension header: the code is 44. This extension header is used when the sender must segment data beyond the MTU. The extension header exists in each data segment. L Authentication Header (Authentication Header) extension Header: Code 51. Encapsulate IPSec data. L ESP extension header: the code is 50. Encapsulate IPSec data. L TCP: the code is 6. Indicates carrying TCP data. L UDP: the code is 17. Indicates carrying UDP data. L Mobility extension header: the code is 135. For mobile nodes. 64 bits are attached in units. Multiple extended packet header layers are nested. The internal extension header is indicated by the next header field in the outer extension header. If the packet carries upper-layer data, the last header field is used to indicate the transport layer protocol, such as TCP or UDP. If no upper-layer data is carried, that is, there is no next header, the value of the next header is 59. The Code is as follows: l Hop-by-Hop option: the code is 0. It is used to carry optional information. All routers on the path through which the data packet passes must process this optional information. The structure of optional information includes three parts: optional data type, optional data length, and optional data. RFC2460 appendix B describes how to define an optional data structure. L Destination option extension header: the code is 60. It carries optional information that only needs to be processed by the destination node of the data packet. The structure of optional information includes three parts: optional data type, optional data length, and optional data. L Routing extension header: the code is 43. Defines the source route. The data section in the extension header lists the node addresses that must pass through a series of data packets to their destination. L Fragment extension header: the code is 44. This extension header is used when the sender must segment data beyond the MTU. The extension header exists in each data segment. L Authentication Header (Authentication Header) extension Header: Code 51. Encapsulate IPSec data. L ESP extension header: the code is 50. Encapsulate IPSec data. L TCP: the code is 6. Indicates carrying TCP data. L UDP: the code is 17. Indicates carrying UDP data. L Mobility extension header: the code is 135. For mobile nodes.