| 791 | Internet ProtocolJ. Postel | Internet Standard | September 1981 |
| 793 | Transmission Control ProtocolJ. Postel · obsoleted by RFC 9293 | Internet Standard | September 1981 |
| 2119 | Key words for use in RFCs to Indicate Requirement LevelsS. Bradner | Best Current Practice | March 1997 |
| 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 |
| 2407 | The Internet IP Security Domain of Interpretation for ISAKMPD. Piper · obsoleted by RFC 4306 | Historic | November 1998 |
| 2408 | Internet Security Association and Key Management Protocol (ISAKMP)D. Maughan, M. Schertler, M. Schneider, J. Turner · obsoleted by RFC 4306 | Historic | November 1998 |
| 2409 | The Internet Key Exchange (IKE)D. Harkins, D. Carrel · obsoleted by RFC 4306 | Historic | November 1998 |
| 2663 | IP Network Address Translator (NAT) Terminology and ConsiderationsP. Srisuresh, M. Holdrege | Informational | August 1999 |
| 2960 | Stream Control Transmission ProtocolR. Stewart, Q. Xie, K. Morneault, C. Sharp, H. Schwarzbauer, T. Taylor, I. Rytina, M. Kalla, L. Zhang, V. Paxson · obsoleted by RFC 4960 | Proposed Standard | October 2000 |
| 3022 | Traditional IP Network Address Translator (Traditional NAT)P. Srisuresh, K. Egevang | Informational | January 2001 |
| 3056 | Connection of IPv6 Domains via IPv4 CloudsB. Carpenter, K. Moore | Proposed Standard | February 2001 |
| 3102 | Realm Specific IP: FrameworkM. Borella, J. Lo, D. Grabelsky, G. Montenegro | Experimental | October 2001 |
| 3103 | Realm Specific IP: Protocol SpecificationM. Borella, D. Grabelsky, J. Lo, K. Taniguchi | Experimental | October 2001 |
| 3104 | RSIP Support for End-to-end IPsecG. Montenegro, M. Borella | Experimental | October 2001 |
| 3193 | Securing L2TP using IPsecB. Patel, B. Aboba, W. Dixon, G. Zorn, S. Booth | Proposed Standard | November 2001 |
| 3309 | Stream Control Transmission Protocol (SCTP) Checksum ChangeJ. Stone, R. Stewart, D. Otis · obsoleted by RFC 4960 | Proposed Standard | September 2002 |
| 3456 | Dynamic Host Configuration Protocol (DHCPv4) Configuration of IPsec Tunnel ModeB. Patel, B. Aboba, S. Kelly, V. Gupta | Proposed Standard | January 2003 |