
72 Part One • Theory
IP options from the main header. The options headers, if any, are simply
inserted into the datagram after the header and before the transport layer
protocol header. This way, routers can process datagrams without having
to process the options headers unless it is necessary—thus improving
performance overall for all datagrams.
RFC 1710 provides both a technical overview to the SIPP specification and
a readable justification and narrative of the protocol. It is worth a look, if
only to see how IPv6 as we know it came to be—because SIPP, with some
modifications, was the specification recommended to and accepted by the
IESG as the basis