Chronophage.net Blog

[Originally Appeared 02/04/2010 blogs.iphouse.net]

One of the many terms you’ll hear thrown around an internet service provider is Request For Comments, aka, RFC: “This isn’t per the RFC!” or “We follow the RFC!” or “Read the RFC!” So what is an RFC, and why do you want to know what it says.

RFCs are, in a nutshell, the description of how a program, or procedure should work. The history of RFC is long and boring, but basically, they’ve been around since the ARPANET Project began, as written or typed memo that were literally Requests for Comments, open ended questions that someone wanted to solicit answers to. As ARPANET grew, RFCs became the standard way to record procedure, and a way for people to implement the fundamental technologies that make up the Internet as it stands today. Today, RFCs are managed by the Internet Engineering Task Force.

RFCs are numbered in chronological order, and serve as sort of a timeline of the Internet and its protocols, and their modifications. Many a bar bet has been settle by referring to an RFC index.

RFCs are referred to by their number, and many of these numbers pop up, especially in error messages. For example, mail headers (the information that records how an email was processed) was originally covered by RFC 821, so you’ll often see errors in a mail log that references RFC 821. The same goes for HTML, USENET, DNS, etc… The errors are written that way because the creators want to emphasize that they follow the RFCs, and so should you.

Why are RFCs important? Well, it boils down to communication theory. The Internet at large is basically an anarchy. There are no overriding rules. It’s just data going back and forth. The only way that too entities can communicate with each other is if they agree to. RFCs are a way to manage these agreements. It’s a way to say: “I follow these rules, and if you don’t, don’t expect me to understand what you’re saying.” If you write a program that follows the RFCs properly, you can expect other correctly written programs to understand what’s going on.

Some companies don’t follow RFCs, they try to use their marketing positions and user base to, what one calls “Embrace and Extend” certain protocols. They more or less want to pollute the internet with their own way of doing things, so that they can control who talks to their users, and who their users talk to. Many others are very strict about their interpretation of the RFCs, causing users to get caught in the middle of Open Standards vs Commercial Protocols. This war is hardly limited to RFCs, there are all sorts of standards bodies that companies ignore. Furthermore, RFCs tend to be vague about specific actions. There’s a lot of “you can,” “you should,” and “it is recommended,” talk in most of them. This often leads to arguments about what is allowed and what is not “per an RFC.”

Like I said, anarchy.

Ultimately, RFCs are holy writ to some, and merely “guidelines” to others. Most UN*X Admins follow RFCs and “Best Practices” as best they can. Many others do not. How important is it to follow them? Well, most of the Internet is still run on programs that use open protocols. So far, most initiatives to commandeer them by commercial entities have failed.

I personally believe in open standards, so if you expect to talk to me, or any my systems, you better read the RFC!

I hope that helps.