The IP Authentication Header is used to provide connectionless integrity and data origin authentication for IP datagrams and to provide protection against replays. http://www.ietf.org/rfc/rfc2402.txt.
| Field Name | Type | Description |
|---|---|---|
| Next_Header0..1 | IANAAssignedIPNumbersType |
Identifies the type of header immediately following the Authentication header. Uses the same values as the IPv4 Protocol field. |
| Header_Ext_Len0..1 | HexBinaryObjectPropertyType |
An 8-bit field specifying the length of the AH in 32-bit words. |
| Security_Parameters_Index0..1 | HexBinaryObjectPropertyType |
The SPI is an arbitrary 32-bit value that, in combination with the destination IP address and security protocol (AH), uniquely identifies the Security Association for this datagram. The set of SPI values in the range 1 through 255 are reserved by the Internet Assigned Numbers Authority (IANA) for future use. http://www.ietf.org/rfc/rfc2402.txt. |
| Sequence_Number0..1 | HexBinaryObjectPropertyType |
This unsigned 32-bit field contains a monotonically increasing counter value (sequence number). |
| Authentication_Data0..1 | HexBinaryObjectPropertyType |
This is a variable-length field that contains the Integrity Check Value (ICV) for this packet. The field must be an integer multiple of 32 bits in length. |