Section 5.5. Overview of New IPsec RFCs

Table 5-4 contains a comparison of the old and new RFCs for your reference.

Table 5-4. Overview of RFCs
Old specification	Title	New specification
RFC 2401	Security Architecture for the Internet Protocol	RFC 4301 (obsoletes 2401)
RFC 2402	IP Authentication Header	RFC 4302 (obsoletes 2402)
RFC 2404	Cryptographic Algorithm Implementation Requirements for Encapsulating Security Payload (ESP) and Authentication Header (AH)	RFC 4305 (obsoletes 2404 and 2406)
RFC 2406	IP Encapsulating Security Payload (ESP)	RFC 4303 and RFC 4305 (obsolete 2406)
RFC 2407	IKEv2	RFC 4306 (obsoletes 2407, 2408, 2409)
RFC 2408
RFC 2409
N/A	Cryptographic Algorithms for Use in the Internet Key Exchange Version 2 (IKEv2)	RFC 4307
N/A	Cryptographic Suites for IPsec	RFC 4308
N/A	Using Advanced Encryption Standard (AES) CCM Mode with IPsec Encapsulating Security Payload (ESP)	RFC 4309
RFC 2409	IKEv1	RFC 4109 (updates 2409)

Until IKEv2 is universally adopted, it is important that nodes support IKEv1 by supporting RFCs 2407, 2408, 2409, and 4109.