RFC(Request For Comments)-意即“请求注解”，包含了关于Internet的几乎所有重要的文字资料。如果你想成为网络方面的专家，那么RFC无疑是*重要也是*经常需要用到的资料之*，所以RFC享有网络知识圣经之美誉。
RFC起始于1969年（当时 Internet 是 ARPANET）。RFC 文档主要涉及计算处理和计算机通信方面的网络技术协议、过程、程序和理论概念，但同时也包括会议记录、评价和*些幽默片段。这种英特网协议组规范文档，由 Internet 工程任务组（IETF）及 Internet 工程指导小组（IESG）共同制定，命*为 RFCs。许多 TCP/IP 协议和 PPP 产品都包含在 RFC 中。
Internet 工程任务组（IETF）隶属于 Internet 架构委员会（IAB），该组织*初由 US 政府建立，现在已成为*个开放式的自治组织机构。IAB 在底层 TCP/IP 协议的 R&D 中发挥着重要的协调作用，并引导着英特网的发展。TCP/IP 协议和许多其它协议在 RFC 中都有详细的讲解和阐述，每*份文档都需经过 IETF 委员会的起草、讨论、宣传和批准等环节。所有文档都是公开和免费使用的，读者可以在相关链接中的 IETF 站点实现在线查看。
通常，当某家机构或团体开发出了*套标准或提出对某种标准的设想，想要征询外界的意见时，就会在Internet上发放*份RFC，对这*问题感兴趣的人可以阅读该RFC并提出自己的意见；绝大部分网络标准的指定都是以RFC的形式开始，经过大量的论证和修改过程，由主要的标准化组织所指定的，但在RFC中所收录的文件并不都是正在使用或为大家所公认的，也有很大*部分只在某个局部领域被使用或并没有被采用，*份RFC具体处于什么状态都在文件中作了明确的标识。
截止到2001年中期，公布的RFC大约有3000余篇，以下是几个较为稳定的RFC链接，以及几个重要的标准化组织的网站链接
- http://www.rfc.net RFC的官方站点，可以检查RFC*及时的更新情况
- http://www.ietf.org *重要的Internet组织之*
- http://sunsite.dk RFC查询非常强大(可以以FTP登录下载全部RFC文档)
- http://www.iso.ch ISO-国际标准化组织
- http://standards.ieee.org IEEE-电气与电子工程师协会
- http://web.ansi.org ANSI-美国国家标准化组织
- http://www.itu.int ITU-国际电信同盟
RFC分类检索：
以下根据RFC被公布时的状态把RFC索引划分成几类：
Standards(标准) Draft Standards(草案标准) Proposed Standards(提案标准)
OTHER RFCS(其他RFC)
Experimental(实验性的) Informational(知识性的) Historic(历史性的)
Early RFCs (before IETF standards track 早期的，在IETF标准化之前)
RFC SUB-SERIES(RFC子集)
Standards (标准，STD) Best Current Practice (**当前实现，BCP)
For Your Information (FYI)
RFC文档下载
推荐RFC英文站点：
http://www.rfc-editor.org/
http://www.faqs.org/rfcs/
Supported Internet RFCs and Drafts
ATM
* RFC 1483, Multiprotocol Encapsulation over ATM Adaptation Layer 5 (routed Protocol Data Units only)
* RFC 2225, Classical IP and ARP over ATM (responses only)
BGP
* RFC 1771, A Border Gateway Protocol 4 (BGP-4)
* RFC 1772, Application of the Border Gateway Protocol in the Internet
* RFC 1965, Autonomous System Confederations for BGP
* RFC 1966, BGP Route Reflection—An Alternative to Full-Mesh IBGP
* RFC 1997, BGP Communities Attribute
* RFC 2270, Using a Dedicated AS for Sites Homed to a Single Provider
* RFC 2283, Multiprotocol Extensions for BGP-4
* RFC 2385, Protection of BGP Sessions via the TCP MD5 Signature Option
* RFC 2439, BGP Route Flap Damping
* Capabilities Negotiation with BGP4, IETF draft draft-ietf-idr-cap-neg-01
CHAP
* RFC 1994, PPP Challenge Handshake Authentication Protocol (CHAP)
Frame Relay
* RFC 1490, Multiprotocol Interconnect over Frame Relay
GRE and IP-IP Encapsulation
* RFC 1701, Generic Routing Encapsulation (GRE)
* RFC 1702, Generic Routing Encapsulation over IPv4 Networks
* RFC 2003, IP Encapsulation within IP
IP Multicast
* RFC 1112, Host Extensions for IP Multicasting (defines IGMP Version 1)
* RFC 2236, Internet Group Management Protocol, Version 2
* Internet Group Management Protocol, Version 3, Internet Draft
draft-ietf-idmr-igmp-v3-07.txt (only SAP, Version 0 and 1)
* RFC 2327, SDP: Session Description Protocol
* RFC 2362, Protocol Independent Multicast-Sparse Mode (PIM-SM): Protocol Specification
* RFC 2365, Administratively Scoped IP Multicast
* Protocol Independent Multicast-Sparse Mode (PIM-SM): Protocol Specification, Internet Draft draft-ietf-idmr-pim-sm-specv2-00
* Protocol Independent Multicast-Version 2 Dense Mode Specification, Internet Draft draft-ietf-pim-v2-dm-03
* Distance Vector Multicast Routing Protocol, Internet draft draft-ietf-idmr-dvmrp-v3-07
* SAP: Session Announcement Protocol, Internet draft draft-ietf-mmusic-sap-00
* Multicast Source Discovery Protocol (MSDP), Internet draft draft-ietf-msdp-spec-01.txt
* Anycast RP Mechanism using PIM and MSDP, Internet draft draft-ietf-mboned-anycast-rp-05.txt
IS-IS
* RFC 1195, Use of OSI IS-IS for Routing in TCP/IP and Dual Environments
* RFC 2104, HMAC: Keyed-Hashing for Message Authentication
* RFC 2763, Dynamic Hostname Exchange Mechanism for IS-IS
* RFC 2966, Domain-wide Prefix Distribution with Two-Level IS-IS
* RFC 2973, IS-IS Mesh Groups
* IS-IS Extensions for Traffic Engineering, Internet draft draft-ietf-isis-traffic-02.txt
* Three-Way Handshake for IS-IS Point-to-Point Adjacencies, Internet draft draft-ietf-isis-3way-03.txt
IPSec and IKE
* RFC 2085, HMAC-MD5 IP Authentication with Replay Prevention
* RFC 2401, Security Architecture for the Internet Protocol
* RFC 2402, IP Authentication Header (except for ES PIC)
* RFC 2403, The Use of HMAC-MD5-96 within ESP and AH
* RFC 2404, The Use of HMAC-SHA-1-96 within ESP and AH
* RFC 2405, The ESP DES-CBC Cipher Algorithm With Explicit IV
* RFC 2406, IP Encapsulation Security Payload
* RFC 2407, The Internet IP Security Domain of Interpretation for ISAKMP
* RFC 2408, Internet Security Association and Key Management Protocol (ISAKMP)
* RFC 2409, Internet Key Exchange
* RFC 2410, The NULL Encryption Algorithm and Its Use With IPSec
* RFC 2412, The OAKLEY Key Determination Protocol
IPv6
* ISO/IEC 10589, Information technology, Telecommunications and information exchange between systems, Intermediate system to intermediate system intradomain routing information exchange protocol for use in conjunction with the protocol for providing the
connectionless-mode network service (ISO 8473)
* RFC 1157, A Simple Network Management Protocol (SNMP)
* RFC 1213, Management Information Base for Network Management of TCP/IP-Based Internets: MIB-II
* RFC 1215, A Convention for Defining Traps for Use with SNMP
* RFC 1195, Use of OSI IS-IS for Routing in TCP/IP and Dual Environments
* RFC 1771, A Border Gateway Protocol 4 (BGP-4)
* RFC 1772, Application of the Border Gateway Protocol in the Internet
* RFC 1901, Introduction to Community-based SNMPv2
* RFC 1902, Structure of Management Information for Version 2 of the Simple Network Management Protocol (SNMPv2)
* RFC 1905, Protocol Operations for Version 2 of the Simple Network Management Protocol (SNMPv2)
* RFC 1965, Autonomous System Confederations for BGP
* RFC 1966, BGP Route Reflection: An Alternative to Full-Mesh IBGP
* RFC 1997, BGP Communities Attribute
* RFC 2080, RIPng for IPv6
* RFC 2081, RIPng Protocol Applicability Statement
* RFC 2270, Using a Dedicated AS for Sites Homed to a Single Provider
* RFC 2283, Multiprotocol Extensions for BGP-4
* RFC 2373, IP Version 6 Addressing Architecture
* RFC 2385, Protection of BGP Sessions via the TCP MD5 Signature Option
* RFC 2439, BGP Route Flap Damping
* RFC 2545, Use of BGP-4 Multiprotocol Extensions for IPv6 Inter-Domain Routing
* RFC 2460, Internet Protocol, Version 6 (IPv6) Specification
* RFC 2461, Neighbor Discovery for IP Version 6 (IPv6)
* RFC 2578, Structure of Management Information Version 2 (SMIv2)
* RFC 2763, Dynamic Hostname Exchange Mechanism for IS-IS
* RFC 2893, Transition Mechanisms for IPv6 Hosts and Routers
* Routing IPv6 with IS-IS, IETF Draft draft-ietf-isis-ipv6-02.txt
* Capabilities Negotiation with BGP4, IETF Draft draft-ietf-idr-cap-neg-01.txt
* BGP Extended Communities Attribute, IETF draft-ramachandra-bgp-ext-communities-09.txt
LDP
* Label Distribution Protocol (LDP)—Version 1 Functional Specification,(draft-ietf-mpls-ldp-06.txt)
MIBs
* IEEE, 802.3ad, Aggregation of Multiple Link Segments (only the objects dot3adAggMACAddress, dot3adAggAggregateOrIndividual, dot3adAggPortListPorts, dot3adAggPortStatsMarkerPDUsRx, dot3adAggPortStatsMarkerResponsePDUsRx, dot3adAggPortStatsMarkerPDUsTx, dot3adAggPortStatsMarkerResponsePDUsTx, and dot3adTablesLastChanged)
* RFC 1213, Management Information Base for Network Management of TCP/IP-based internets: MIB-II
* RFC 1215, Convention for defining traps for use with the SNMP
* RFC 1657, Definitions of Managed Objects for the Fourth Version of the Border Gateway Protocol (BGP-4) using SMIv2
* RFC 1850, OSPF Version 2 Management Information Base (except for the ospfOriginateNewLsas and ospfRxNewLsas objects, the Host Table, and the traps ospfOriginateLSA, ospfLsdbOverflow, and ospfApproachingLsdbOverflow)
* RFC 1906, Transport Mappings for Version 2 of the Simple Network Management Protocol
* RFC 1907, Management Information Base for Version 2 of the Simple Network Management Protocol (SNMPv2)
* RFC 2011, SNMPv2 Management Information Base for the Internet Protocol using SMIv2
* RFC 2012, SNMPv2 Management Information Base for the Transmission Control Protocol using SMIv2
* RFC 2013, SNMPv2 Management Information Base for the User Datagram Protocol using SMIv2
* RFC 2096, IP Forwarding Table MIB
* RFC 2115, Management Information Base for Frame Relay DTEs Using SMIv2
* RFC 2233, The Interfaces Group MIB-II using SMIv2
* RFC 2495, Definitions of Managed Objects for the DS1, E1, DS2, and E2 Interface Types (except for dsx1FarEndConfigTable, dsx1FarEndCurrentTable, dsx1FarEndIntervalTable, dsx1FarEndTotalTable, and dsx1FracTable)
* RFC 2496, Definitions of Managed Object for the DS3/E3 Interface Type
* RFC 2515, Definitions of Managed Objects for ATM Management
* RFC 2558, Definitions of Managed Objects for the SONET/SDH Interface Type
* RFC 2665, Definitions of Managed Objects for the Ethernet-like Interface Types
* RFC 2790, Host Resources MIB (only the objects of the hrSystem and hrSWInstalled groups)
* RFC 2819, Remote Network Monitoring Management Information Base (the etherStatsTable for Ethernet interfaces only)
* RFC 2925, Definitions of Managed Objects for Remote Ping, Traceroute, and Lookup Operations (only PingMIB ).
* RFC 2932, IPv4 Multicast Routing MIB
* IANAiftype Textual Convention MIB, Internet Assigned Numbers Authority (referenced by RFC 2233, available at ftp://ftp.isi.edu/mib/ianaiftype.mib)
* Internet Group Management Protocol (IGMP) MIB, Internet draft draft-ietf-idmr-igmp-mib-13.txt
* Protocol Independent Multicast (PIM) MIB, Internet draft draft-ietf-idmr-pim-mib-09.txt
MPLS
* RFC 2205, Resource ReSerVation Protocol (RSVP)—Version 1 Functional Specification
* RFC 2209, Resource ReSerVation Protocol (RSVP)—Version 1 Message Processing Rules
* RFC 2961, RSVP Refresh Overhead Reduction Extensions
* RFC 2210, The Use of RSVP with IETF Integrated Services
* RFC 2211, Specification of the Controlled-Load Network Element Service
* RFC 2215, General Characterization Parameters for Integrated Service Network Elements
* RFC 2216, Network Element Service Specification Template
* RFC 2702, Requirements for Traffic Engineering Over MPLS
* ICMP Extensions for Multiprotocol Label Switching, Internet draft draft-ietf-mpls-icmp-01.txt
* MPLS Label Stack Encoding, Internet draft draft-ietf-mpls-label-encaps-07.txt
* Extensions to RSVP for LSP Tunnels, Internet draft draft-ietf-mpls-rsvp-lsp-tunnel-05.txt
* BGP/MPLS VPNs, Internet Draft draft-ietf-ppvpn-rfc2547bis-00.txt
* MPLS-based Layer 2 VPNs, Internet Draft draft-kompella-ppvpn-l2vpn-00.txt
* Transport of Layer 2 Frames Over MPLS, Internet Draft
draft-martini-l2circuit-trans-mpls-07.txt
OSPF
* RFC 1587, The OSPF NSSA Option
* RFC 2328, OSPF Version 2
* Traffic Engineering Extensions to OSPF, Internet draft draft-katz-yeung-ospf-traffic-01.txt
PPP
* RFC 1332, The PPP Internet Protocol Control Protocol (IPCP)
* RFC 1661, The Point-to-Point Protocol (PPP)
* RFC 1662, PPP in HDLC-like Framing
* RFC 2615, PPP over SONET/SDH
RIP
* RFC 1058, Routing Information Protocol
* RFC 2453, RIP Version 2
RSVP
* RFC 2205, Resource ReSerVation Protocol (RSVP), Version 1, Functional Specification
* RFC 2209, Resource ReSerVation Protocol (RSVP), Version 1, Message Processing Rules
* RFC 2210, The Use of RSVP with IETF Integrated Services
* RFC 2211, Specification of the Controlled-Load Network Element Service
* RFC 2212, Specification of Guaranteed Quality of Service
* RFC 2215, General Characterization Parameters for Integrated Service Network Elements
* RFC 2216, Network Element Service Specification Template
* RFC 2747, RSVP Cryptographic Authentication
* Extensions to RSVP for LSP Tunnels, Internet draft draft-ietf-mpls-rsvp-lsp-tunnel-05.txt
* RSVP Refresh Reduction Extensions, Internet draft draft-ietf-rsvp-refresh-reduct-05.txt
TCP/IP v4
* RFC 768, User Datagram Protocol
* RFC 791, Internet Protocol
* RFC 792, Internet Control Message Protocol
* RFC 793, Transmission Control Protocol
* RFC 826, Ethernet Address Resolution Protocol
* RFC 854, Telnet Protocol Specification
* RFC 862, Echo Protocol
* RFC 863, Discard Protocol
* RFC 896, Congestion Control in IP/TCP Internetworks
* RFC 919, Broadcasting Internet Datagrams
* RFC 922, Broadcasting Internet Datagrams in the Presence of Subnets
* RFC 959, File Transfer Protocol
* RFC 1027, Using ARP to Implement Transparent Subnet Gateways
* RFC 1042, Standard for the Transmission of IP Datagrams over IEEE 802 Networks
* RFC 1157, Simple Network Management Protocol (SNMP)
* RFC 1166, Internet Numbers
* RFC 1195, Use of OSI IS-IS for Routing in TCP/IP and Dual Environments
* RFC 1256, ICMP Router Discovery Messages
* RFC 1305, Network Time Protocol (Version 3) Specification, Implementation, and Analysis
* RFC 1519, Classless Inter-Domain Routing (CIDR): An Address Assignment and Aggregation Strategy
* RFC 1812, Requirements for IP Version 4 Routers
* RFC 2338, Virtual Router Redundancy Protocol
Supported ISO Standards
IS-IS
* ISO/IEC 10589, Information technology, Telecommunications and information exchange between systems, Intermediate system to intermediate system intradomain routing information exchange protocol for use in conjunction with the protocol for providing the connectionless-mode network service (ISO 8473)
Supported SDH and SONET Standards
* ANSI T1.105, Synchronous Optical Network (SONET) Basic Description Including Multiplex Structures, Rates, and Formats
* ANSI T1.105.02, Synchronous Optical Network (SONET) Payload Mappings
* ANSI T1.105.06, SONET: Physical Layer Specifications
* GR-253-CORE, SONET Transport Systems: Common Generic Criteria
* GR-499-CORE, Transport System Generic Requirements (TSGR): Common Requirements
* GR-1377-CORE, SONET OC-192 Transport System Generic Criteria
* ITU-T Recommendation G.691, Optical interfaces for single channel SDH systems with optical amplifiers, and STM-64 systems
* ITU-T Recommendation G.707 (1996), Network node interface for the synchronous digital hierarchy (SDH)
* ITU-T Recommendation G.783 (1994), Characteristics of Synchronous Digital Hierarchy (SDH) equipment functional blocks
* ITU-T Recommendation G.813 (1996), Timing characteristics of SDH equipment slave clocks (SEC)
* ITU-T Recommendation G.825 (1993), The control of jitter and wander within digital networks which are based on the Synchronous Digital Hierarchy (SDH)
* ITU-T Recommendation G.826 (1999), Error performance parameters and objectives for international, constant bit rate digital paths at or above the primary rate
* ITU-T Recommendation G.831 (1993), Management capabilities of transport networks based on Synchronous Digital Hierarchy (SDH)
* ITU-T Recommendation G.957 (1995), Optical interfaces for equipment and systems relating to the synchronous digital hierarchy
* ITU-T Recommendation G.958 (1994), Digital line systems based on the Synchronous Digital Hierarchy for use on optical fibre cables
* ITU-T Recommendation I.432 (1993), B-ISDN User-Network Interface Physical layer specification
Other Supported Standards
ATM
* ITU-T Recommendation I.363, B-ISDN ATM adaptation layer sublayers: service-specific coordination function to provide the connection-oriented transport service (JUNOS software conforms only to the AAL5/IP over ATM portion of this standard)
* ITU-T Recommendation I.432.3, B-ISDN user-network interface Physical layer specifications: 51,840 kbits/s operation
Frame Relay
* ANSI T1.617-1991, Annex D, Additional procedures for permanent virtual connections (PVCs) using unnumbered information frames
* ITU Q.933a, Annex A, Additional Procedures for Permanent Virtual Connections (PVC) status management (using Unnumbered Information frames)
Ethernet
* IEEE, 802.3ad, Aggregation of Multiple Link Segments
* IEEE, 802.3, Carrier Sense Multiple Access with Collision Detection (CSMA/CD)
T3
* ITU-T Recommendation G.703, Physical/electrical characteristics of hierarchical digital interfaces