About rfc.dk

rfc.dk is an independent mirror of the RFC series - the documents that define the protocols and practices of the Internet, from RFC 1 in 1969 to the latest publication. It exists to make the series fast to read and easy to search.

What is an RFC?

A Request for Comments is a publication from the RFC Editor, produced by the Internet Engineering Task Force (IETF), the Internet Research Task Force (IRTF), the Internet Architecture Board (IAB) and independent authors. Despite the humble name, RFCs on the standards track are the official specifications of the Internet: TCP, IP, HTTP, TLS, DNS, SMTP and QUIC are all defined in RFCs. Others are informational, experimental, or record best current practice.

How the mirror works

The texts and the metadata index (rfc-index.xml) are fetched from the RFC Editor's official rsync service several times a day. New or changed documents are indexed into a full-text search database and appear on the site immediately after each synchronisation. Nothing is edited: the text you read here is byte for byte what the RFC Editor published. Cross-references to other RFCs and URLs are linked for convenience.

URLs

• /rfc9000/ - RFC 9000 with metadata and the full text
• /rfc9000.txt - the original plain-text file
• /9000, /rfc09000, /rfc9000.html - redirect to the page
• /rfc9000.json - the metadata as JSON; /rfc9000/cited-by/ and /rfc9000/cites/ - citation lists
• /std/, /bcp/, /fyi/ - the subseries; /bcp14 jumps to BCP 14
• /wg/quic/, /area/sec/, /author/j-postel/ - RFCs by working group, area or author
• /browse/2021/, /browse/9000-9099/ - lists by year or number range
• /search?q=… - full-text search; /feed.xml - RSS feed of new RFCs

Search

Search covers titles, abstracts, keywords and the complete text of every RFC. Words of five letters or more match as prefixes, "quoted words" match as a phrase, OR and -word work as expected, and title:, author:, wg:, area:, stream:, status: and year: narrow a query - the search help has examples of everything. Results rank title matches highest, demote obsoleted and historic documents, and favour RFCs that many other RFCs cite. Typing a number opens that RFC directly; &format=json returns results as JSON.

Reading

Section headings in the text are anchors (#section-4.2, #appendix-A), the table of contents and every "Section 4.2" or "Section 3 of [RFC7231]" reference is a link, and long RFCs get a contents panel beside the text. Each page also shows which RFCs the document cites and which cite it, derived from the texts themselves.

Credits and licence

RFCs are copyright their authors and the IETF Trust; see the Trust Legal Provisions. rfc.dk is run privately from Denmark and is not affiliated with the RFC Editor, the IETF or the Internet Society.

Contact

Questions about the mirror, broken links, or a problem with the site: write to info [at] rfc.dk. Please note that the site owner has no part in writing or publishing the RFCs themselves. Comments on the content of a document belong with its authors and the RFC Editor - each RFC page links to its errata and to the Datatracker, where the responsible working group can be found.