| 2385 | Protection of BGP Sessions via the TCP MD5 Signature OptionA. Heffernan · obsoleted by RFC 5925 | Proposed Standard | August 1998 |
| 2401 | Security Architecture for the Internet ProtocolS. Kent, R. Atkinson · obsoleted by RFC 4301 | Proposed Standard | November 1998 |
| 2402 | IP Authentication HeaderS. Kent, R. Atkinson · obsoleted by RFC 4302, RFC 4305 | Proposed Standard | November 1998 |
| 2406 | IP Encapsulating Security Payload (ESP)S. Kent, R. Atkinson · obsoleted by RFC 4303, RFC 4305 | Proposed Standard | November 1998 |
| 2409 | The Internet Key Exchange (IKE)D. Harkins, D. Carrel · obsoleted by RFC 4306 | Historic | November 1998 |
| 2461 | Neighbor Discovery for IP Version 6 (IPv6)T. Narten, E. Nordmark, W. Simpson · obsoleted by RFC 4861 | Draft Standard | December 1998 |
| 2661 | Layer Two Tunneling Protocol "L2TP"W. Townsley, A. Valencia, A. Rubens, G. Pall, G. Zorn, B. Palter | Proposed Standard | August 1999 |
| 3547 | The Group Domain of InterpretationM. Baugher, B. Weis, T. Hardjono, H. Harney · obsoleted by RFC 6407 | Proposed Standard | July 2003 |
| 3552 | Guidelines for Writing RFC Text on Security ConsiderationsE. Rescorla, B. Korver | Best Current Practice | July 2003 |
| 3554 | On the Use of Stream Control Transmission Protocol (SCTP) with IPsecS. Bellovin, J. Ioannidis, A. Keromytis, R. Stewart | Proposed Standard | July 2003 |
| 3715 | IPsec-Network Address Translation (NAT) Compatibility RequirementsB. Aboba, W. Dixon | Informational | March 2004 |
| 3830 | MIKEY: Multimedia Internet KEYingJ. Arkko, E. Carrara, F. Lindholm, M. Naslund, K. Norrman | Proposed Standard | August 2004 |
| 3948 | UDP Encapsulation of IPsec ESP PacketsA. Huttunen, B. Swander, V. Volpe, L. DiBurro, M. Stenberg | Proposed Standard | January 2005 |
| 4107 | Guidelines for Cryptographic Key ManagementS. Bellovin, R. Housley | Best Current Practice | June 2005 |
| 4271 | A Border Gateway Protocol 4 (BGP-4)Y. Rekhter, Ed., T. Li, Ed., S. Hares, Ed. | Draft Standard | January 2006 |
| 4301 | Security Architecture for the Internet ProtocolS. Kent, K. Seo | Proposed Standard | December 2005 |
| 4302 | IP Authentication HeaderS. Kent | Proposed Standard | December 2005 |
| 4303 | IP Encapsulating Security Payload (ESP)S. Kent | Proposed Standard | December 2005 |
| 4306 | Internet Key Exchange (IKEv2) ProtocolC. Kaufman, Ed. · obsoleted by RFC 5996 | Proposed Standard | December 2005 |
| 4430 | Kerberized Internet Negotiation of Keys (KINK)S. Sakane, K. Kamada, M. Thomas, J. Vilhuber | Proposed Standard | March 2006 |
| 4535 | GSAKMP: Group Secure Association Key Management ProtocolH. Harney, U. Meth, A. Colegrove, G. Gross | Proposed Standard | June 2006 |
| 4960 | Stream Control Transmission ProtocolR. Stewart, Ed. · obsoleted by RFC 9260 | Proposed Standard | September 2007 |
| 5280 | Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) ProfileD. Cooper, S. Santesson, S. Farrell, S. Boeyen, R. Housley, W. Polk | Proposed Standard | May 2008 |
| 5374 | Multicast Extensions to the Security Architecture for the Internet ProtocolB. Weis, G. Gross, D. Ignjatic | Proposed Standard | November 2008 |