SECURITY PARAMETERS INDEX The Security Parameters Index is a 32-bit number used to identify the security association of a datagram in certain security procedures [RFC1826, RFC1827]. The first 256 SPI values are assigned by the IANA and listed here. Number Description -------------- ------------------------------------------------------------- 0 Reserved - Used to indicate that no security association has been established [RFC1827] 1 SKIP - [Markson] 1 - 255 Reserved by the IANA DOCUMENTS [RFC1826] Atkinson, R., "IP Authentication Header", RFC 1826, Naval Research Laboratory, August 1995. [RFC1827] Atkinson, R., "IP Encapsulating Security Payload (ESP)", RFC 1827, Naval Research Laboratory, August 1995. PEOPLE [Markson] Tom Markson, , August 1995. []