- rfc2021: Remote Network Monitoring Management Information Base Version 2 using SMIv2
- rfc2022: Support for Multicast over UNI 3.0/3.1 based ATM Networks
- rfc2030: Simple Network Time Protocol (SNTP) Version 4 for IPv4, IPv6 and OSI
- rfc2032: RTP Payload Format for H.261 Video Streams
- rfc2043: The PPP SNA Control Protocol (SNACP)
- rfc2045: Multipurpose Internet Mail Extensions (MIME) Part One: Format of Internet Message Bodies
- rfc2046: Multipurpose Internet Mail Extensions (MIME) Part Two:Media Types
- rfc2047: MIME (Multipurpose Internet Mail Extensions) Part Three: Message Header Extensions for Non-ASCII Text
- rfc2048: Multipurpose Internet Mail Extensions (MIME) Part Four: Registration Procedures
- rfc2049: Multipurpose Internet Mail Extensions (MIME) Part Five: Conformance Criteria and Examples
- rfc2080: RIPng for IPv6
- rfc2083: PNG (Portable Network Graphics) Specification Version 1.0
- rfc2097: The PPP NetBIOS Frames Control Protocol (NBFCP)
- rfc2114: Data Link Switching Client Access Protocol
- rfc2125: The PPP Bandwidth Allocation Protocol (BAP)
- rfc2126: ISO Transport Service on top of TCP (ITOT)
- rfc2129: Toshiba's Flow Attribute Notification Protocol (FANP) Specification
- rfc2131: Dynamic Host Configuration Protocol
- rfc2132: DHCP Options and BOOTP Vendor Extensions
- rfc2153: PPP Vendor Extensions
- rfc2165: Service Location Protocol
- rfc2166: APPN Implementer's Workshop Closed Pages Document
- rfc2167: Referral Whois (RWhois) Protocol V1.5
- rfc2190: RTP Payload Format for H.263 Video Streams
- rfc2205: Resource ReSerVation Protocol (RSVP) - Version 1 Functional Specification
- rfc2225: Classical IP and ARP over ATM
- rfc2236: Internet Group Management Protocol, Version 2
- rfc2246: The TLS Protocol Version 1.0
- rfc2251: Lightweight Directory Access Protocol (v3)
- rfc2252: Lightweight Directory Access Protocol (v3): Attribute Syntax Definitions
- rfc2253: Lightweight Directory Access Protocol (v3): UTF-8 String Representation of Distinguished Names
- rfc2254: The String Representation of LDAP Search Filters
- rfc2255: The LDAP URL Format
- rfc2256: A Summary of the X.500(96) User Schema for use with LDAPv3
- rfc2281: Cisco Hot Standby Router Protocol (HSRP)
- rfc2284: PPP Extensible Authentication Protocol (EAP)
- rfc2326: Real Time Streaming Protocol (RTSP)
- rfc2327: SDP: Session Description Protocol
- rfc2328: OSPF Version 2
- rfc2332: NBMA Next Hop Resolution Protocol (NHRP)
- rfc2334: Server Cache Synchronization Protocol (SCSP)
- rfc2338: Virtual Router Redundancy Protocol
- rfc2341: Cisco Layer Two Forwarding (Protocol) "L2F"
- rfc2353: APPN/HPR in IP Networks APPN Implementers' Workshop Closed Pages Document
- rfc2362: Protocol Independent Multicast-Sparse Mode (PIM-SM): Protocol Specification
- rfc2364: PPP Over AAL5
- rfc2390: Inverse Address Resolution Protocol
- rfc2401: Security Architecture for the Internet Protocol
- rfc2402: IP Authentication Header
- rfc2406: IP Encapsulating Security Payload (ESP)
- rfc2408: Internet Security Association and Key Management Protocol (ISAKMP)
- rfc2409:The Internet Key Exchange (IKE)
- rfc2411: IP Security Document Roadmap
- rfc2412: The OAKLEY Key Determination Protocol
- rfc2453: RIP Version 2
- rfc2460: Internet Protocol, Version 6 (IPv6) Specification
- rfc2461: Neighbor Discovery for IP Version 6 (IPv6)
- rfc2463: Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification
- rfc2472: IP Version 6 over PPP
- rfc2474: Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers
- rfc2475: An Architecture for Differentiated Services
- rfc2484: PPP LCP Internationalization Configuration Option
- rfc2508: Compressing IP/UDP/RTP Headers for Low-Speed Serial Links
- rfc2516: A Method for Transmitting PPP Over Ethernet (PPPoE)
- rfc2535: Domain Name System Security Extensions
- rfc2578: Structure of Management Information Version 2 (SMIv2)
- rfc2579: Textual Conventions for SMIv2
- rfc2580: Conformance Statements for SMIv2
- rfc2616: Hypertext Transfer Protocol -- HTTP/1.1
- rfc2625: IP and ARP over Fibre Channel
- rfc2631: Diffie-Hellman Key Agreement Method
- rfc2632: S/MIME Version 3 Certificate Handling
- rfc2633: S/MIME Version 3 Message Specification
- rfc2637: Point-to-Point Tunneling Protocol (PPTP)
- rfc2660: The Secure HyperText Transfer Protocol
- rfc2661: Layer Two Tunneling Protocol "L2TP"
- rfc2684: Multiprotocol Encapsulation over ATM Adaptation Layer 5
- rfc2686: The Multi-Class Extension to Multi-Link PPP
- rfc2719: Framework Architecture for Signaling Transport
- rfc2740: OSPF for IPv6
- rfc2743: Generic Security Service Application Program Interface Version 2, Update 1
- rfc2744: Generic Security Service API Version 2 : C-bindings
- rfc2748: The COPS (Common Open Policy Service) Protocol
- rfc2750: RSVP Extensions for Policy Control
- rfc2776: Multicast-Scope Zone Announcement Protocol (MZAP)
- rfc2784: Generic Routing Encapsulation (GRE)
- rfc2818: HTTP Over TLS
- rfc2819: Remote Network Monitoring Management Information Base
- rfc2821: Simple Mail Transfer Protocol
- rfc2828: Internet Security Glossary
- rfc2829: Authentication Methods for LDAP
- rfc2830: Lightweight Directory Access Protocol (v3): Extension for Transport Layer Security
- rfc2858: Multiprotocol Extensions for BGP-4
- rfc2863: The Interfaces Group MIB
- rfc2865: Remote Authentication Dial In User Service (RADIUS)
- rfc2866: RADIUS Accounting
- rfc2910:Internet Printing Protocol/1.1: Encoding and Transport
- rfc2960: Stream Control Transmission Protocol
- rfc2974: Session Announcement Protocol
- rfc2986: PKCS #10: Certification Request Syntax Specification Version 1.7