Dec 19, 2025·8 min
Jon Postel and the Practical Culture Behind Internet Standards
How Jon Postel’s practical standards mindset shaped Internet governance, helping networks interoperate through RFCs, IETF norms, and early coordination.
How Jon Postel’s practical standards mindset shaped Internet governance, helping networks interoperate through RFCs, IETF norms, and early coordination.
Early computer networking wasn’t “one network that got bigger.” It was many separate networks—run by different organizations, built on different hardware, funded by different goals, and designed with different assumptions. Some were academic and collaborative, some were military, and some were commercial. Each network could work fine on its own and still be unable (or unwilling) to talk to the others.
Zooming out, the challenge was straightforward: how do you connect networks that don’t share the same rules?
Addressing formats differed. Message sizes differed. Error handling differed. Even basic expectations like “how long should we wait before retrying?” could vary. Without shared agreements, you don’t get an Internet—you get disconnected islands with a few custom bridges.
Those bridges are expensive to build and easy to break. They also tend to lock people into a vendor or a specific network operator, because the “translation layer” becomes a competitive choke point.
It’s tempting to describe early networking as a protocol war where the “best” technology won. In practice, interoperability often mattered more than technical elegance or market dominance. A protocol that is slightly imperfect but widely implementable can connect more people than a theoretically superior one that only works inside a single ecosystem.
The Internet’s success depended on a culture that rewarded making things work together—across institutions and borders—even when no single entity had the authority to force cooperation.
Jon Postel became one of the most trusted stewards of this cooperation. Not because he held a sweeping government mandate, but because he helped shape the habits and norms that made shared standards believable: write things down clearly, test them in real implementations, and coordinate the boring-but-essential details (like names and numbers) so everyone stays aligned.
This isn’t a technical deep dive into packet formats. It’s about the practical practices and governance choices that made interoperability possible: the standards culture around RFCs, the IETF’s working style, and the quiet coordination work that kept the growing network from splintering into incompatible “mini-Internets.”
Jon Postel wasn’t a famous CEO or a government official. He was a working engineer and editor who spent much of his career at UCLA and later the Information Sciences Institute (ISI), where he helped turn early networking ideas into shared, usable practice.
If you’ve ever typed a domain name, sent an email, or relied on devices from different vendors to “just work” together, you’ve benefited from the kind of coordination Postel quietly provided for decades.
Postel was effective because he treated standards as a public utility: something you maintain so other people can build. He had a reputation for clarity in writing, patience in debate, and persistence in getting details resolved. That combination mattered in a community where disagreements weren’t academic—they could split implementations and strand users.
He also did the unglamorous work: editing and curating technical notes, answering questions, nudging groups toward decisions, and keeping shared registries organized. That steady, visible service made him a reliable reference point when tempers rose or timelines slipped.
A key part of Postel’s influence was that it didn’t depend on formal power. People listened because he was consistent, fair, and deeply knowledgeable—and because he showed up, over and over, to do the work. In other words, he held “authority” the way good maintainers do: by being helpful, predictable, and hard to replace.
The early Internet was a patchwork of universities, labs, contractors, and vendors with different priorities. Postel’s credibility helped those groups cooperate anyway. When someone trusted that a decision was being made for interoperability—not for politics or profit—they were more willing to align their systems, even if it meant compromise.
An RFC—short for Request for Comments—is a public memo that explains how an Internet protocol or practice should work. Think of it as: “here’s the idea, here’s the format, here are the rules—tell us what breaks.” Some RFCs are early sketches; others become widely used standards. The core habit is the same: write it down so other people can build from the same page.
RFCs were deliberately practical. They aimed to be useful to implementers, not impressive to committees. That meant concrete details: message formats, error cases, examples, and the boring-but-critical clarifications that prevent two teams from interpreting the same sentence in opposite ways.
Just as important, RFCs were written to be tested and revised. Publication wasn’t the finish line—it was the start of real-world feedback. If an idea worked in code but failed between networks, the document could be updated or replaced. This “publish early, improve openly” rhythm kept protocols grounded.
When specifications are private, misunderstandings multiply: one vendor hears one explanation, another vendor hears a slightly different one, and interoperability becomes an afterthought.
Making RFCs publicly available helped align everyone—researchers, vendors, universities, and later commercial providers—around the same reference text. Disagreements didn’t disappear, but they became visible and therefore solvable.
A key reason RFCs stayed readable and consistent was editorial discipline. Editors (including Jon Postel for many years) pushed for clarity, stable terminology, and a common structure.
Then the wider community reviewed, questioned assumptions, and corrected edge cases. That mix—strong editing plus open critique—created documents that could actually be implemented by people who weren’t in the original room.
“Rough consensus and running code” is the IETF’s way of saying: don’t settle arguments by debating what might work—build something that does work, show others, then write down what you learned.
Running code isn’t a slogan about loving software. It’s a proof standard:
In practice, this pushes standards work toward prototypes, interoperability demos, test suites, and repeated “try it, fix it, try again” cycles.
Networks are messy: latency varies, links drop, machines differ, and people build things in unexpected ways. By requiring something runnable early, the community avoided endless philosophical debates about the perfect design.
The benefits were practical:
This approach isn’t risk-free. “First working thing wins” can create premature lock-in, where an early design becomes hard to change later. It can also reward teams with more resources, who can build implementations sooner and thus shape the direction.
To keep the culture from turning into “ship it and forget it,” the IETF leaned on testing and iteration. Interoperability events, multiple implementations, and careful revision cycles helped separate “it runs on my machine” from “it works for everyone.”
That’s the core idea: standards as a record of proven practice, not a wish list of features.
“Fragmentation” here doesn’t just mean multiple networks existing at once. It means incompatible networks that can’t talk to each other cleanly, plus duplicated efforts where each group reinvents the same basic plumbing in slightly different ways.
If every network, vendor, or government project had defined its own addressing, naming, and transport rules, connecting systems would have required constant translation. That translation usually shows up as:
The result isn’t only technical complexity—it’s higher prices, slower innovation, and fewer people able to participate.
Shared, public standards made the Internet cheaper to join. A new university network, a startup ISP, or a hardware vendor didn’t need special permission or a bespoke integration deal. They could implement the published specs and expect interoperability with everyone else.
This lowered the cost of experimentation, too: you could build a new application on top of existing protocols without negotiating a separate compatibility pact with every operator.
Avoiding fragmentation required more than good ideas; it required coordination that competing incentives couldn’t easily provide. Different groups wanted different outcomes—commercial advantage, national priorities, research goals—but they still needed a common meeting point for identifiers and protocol behavior.
Neutral coordination helped keep the connective tissue shared, even when the parties building on top of it didn’t fully trust each other. That’s a quiet, practical kind of governance: not controlling the network, but preventing it from splitting into isolated islands.
The Internet Engineering Task Force (IETF) didn’t succeed because it had the most authority. It succeeded because it built a dependable way for lots of independent people and organizations to agree on how the Internet should behave—without requiring any single company, government, or lab to own the outcome.
The IETF operates like a public workshop. Anyone can join mailing lists, read drafts, attend meetings, and comment. That openness mattered because interoperability problems often show up at the edges—where different systems meet—and those edges are owned by many different people.
Instead of treating outside feedback as a nuisance, the process treats it as essential input. If a proposal breaks real networks, someone will usually say so quickly.
Most work happens in working groups, each focused on a specific problem (for example, how email should be formatted, or how routing information should be exchanged). A working group forms when there’s a clear need, enough interested contributors, and a charter that defines scope.
Progress tends to look practical:
Influence in the IETF is earned by showing up, doing careful work, and responding to critique—not by job title. Editors, implementers, operators, and reviewers all shape the result. That creates a useful pressure: if you want your idea adopted, you must make it understandable and implementable.
Open debate can easily turn into endless debate. The IETF developed norms that kept discussions pointed:
The “win” isn’t rhetorical. The win is that independently built systems still manage to work together.
When people talk about how the Internet works, they usually picture big inventions: TCP/IP, DNS, or the web. But a lot of interoperability depends on something less glamorous: everyone agreeing on the same master lists. That’s the basic job of IANA—the Internet Assigned Numbers Authority.
IANA is a coordination function that maintains shared registries so different systems can line up their settings. If two independent teams build software from the same standard, those standards still need concrete values—numbers, names, and labels—so their implementations match in the real world.
A few examples make it tangible:
Without a shared registry, collisions happen. Two groups could assign the same number to different features, or use different labels for the same concept. The result isn’t dramatic failure—it’s worse: intermittent bugs, confusing incompatibilities, and products that work only within their own bubble.
IANA’s work is “boring” in the best way. It turns abstract agreement into everyday consistency. That quiet coordination is what lets standards travel—across vendors, countries, and decades—without constant renegotiation.
Jon Postel is often associated with a rule of thumb that shaped how early Internet software behaved: “be strict in what you send, flexible in what you accept.” It sounds like a technical guideline, but it also acted like a social contract between strangers building systems that had to work together.
“Strict in what you send” means your software should follow the spec closely when producing data—no creative shortcuts, no “everyone knows what I meant.” The goal is to avoid spreading odd interpretations that others must copy.
“Flexible in what you accept” means that when you receive data that’s slightly off—maybe a missing field, unusual formatting, or an edge-case behavior—you try to handle it gracefully rather than crashing or rejecting the connection.
In the early Internet, implementations were uneven: different machines, different programming languages, and incomplete specs being refined in real time. Flexibility let systems communicate even when both sides weren’t perfect yet.
That tolerance bought time for the standards process to converge. It also reduced “forking” pressure—teams didn’t need their own incompatible variant just to get something working.
Over time, being too flexible created problems. If one implementation accepts ambiguous or invalid input, others may depend on that behavior, turning bugs into “features.” Worse, liberal parsing can open security issues (think injection-style attacks or bypasses created by inconsistent interpretation).
The updated lesson is: maximize interoperability, but don’t normalize malformed input. Be strict by default, document exceptions, and treat “accepted but noncompliant” data as something to log, limit, and eventually phase out—compatibility with safety in mind.
Big ideas like “interoperability” can feel abstract until you look at the everyday systems that quietly cooperate every time you open a website or send a message. TCP/IP, DNS, and email (SMTP) are a useful trio because each solved a different coordination problem—and each assumed the others would exist.
Early networks could have ended up as islands: each vendor or country running its own incompatible protocol suite. TCP/IP provided a common “how data moves” foundation that didn’t require everyone to buy the same hardware or run the same operating system.
The key win wasn’t that TCP/IP was perfect. It was good enough, openly specified, and implementable by many parties. Once enough networks adopted it, choosing an incompatible stack increasingly meant choosing isolation.
IP addresses are hard for people and brittle for services. DNS solved the naming problem—turning human-friendly names into routable addresses.
But naming isn’t just a technical mapping. It needs clear delegation: who can create names, who can change them, and how conflicts are prevented. DNS worked because it paired a simple protocol with a coordinated namespace, enabling independent operators to run their own domains without breaking everyone else.
Email succeeded because SMTP focused on a narrow promise: transfer messages between servers using a common format and a predictable conversation.
That loose coupling mattered. Different organizations could run different mail software, storage systems, and spam policies, yet still exchange mail. SMTP didn’t force a single provider or a single user experience—it only standardized the handoff.
Together, these standards form a practical chain: DNS helps you find the right destination, TCP/IP gets packets there, and SMTP defines what the mail servers say to each other once connected.
“Internet governance” can sound like treaties and regulators. In the early Internet, it often looked more like a steady stream of small, practical calls: which numbers are reserved, what a protocol field means, how to publish a correction, or when two proposals should be merged. Postel’s influence came less from formal authority and more from being the person who kept those decisions moving—and documented.
There wasn’t a central “Internet police.” Instead, governance happened through habits that made cooperation the easiest path. When a question arose—say, about a parameter registry or a protocol ambiguity—someone had to pick an answer, write it down, and circulate it. Postel, and later the IANA function he stewarded, provided a clear coordination point. The power was quiet: if you wanted your system to work with everyone else’s, you aligned with the shared choices.
Trust was built through transparent records. RFCs and public mailing list discussions meant decisions weren’t hidden in private meetings. Even when individuals made judgment calls, they were expected to leave an audit trail: rationale, context, and a way for others to challenge or improve it.
Accountability mostly came from implementers and peers. If a decision led to breakage, the feedback was immediate—software failed, operators complained, and alternative implementations exposed edge cases. The real enforcement mechanism was adoption: standards that worked spread; those that didn’t were ignored or revised.
This is why Internet governance often looked like engineering triage: reduce ambiguity, prevent collisions, keep compatibility, and ship something people could implement. The goal wasn’t perfect policy—it was a network that kept interconnecting.
The Internet’s standards culture—lightweight documents, open discussion, and a preference for shipping working implementations—helped different networks interoperate quickly. But the same habits also came with trade-offs that became harder to ignore as the Internet grew from a research project into global infrastructure.
“Open to anyone” didn’t automatically mean “accessible to everyone.” Participation required time, travel (in the early years), English fluency, and institutional support. That created uneven representation and, at times, subtle power imbalances: well-funded companies or countries could show up consistently, while others struggled to be heard. Even when decisions were made in public, the ability to shape agendas and draft text could concentrate influence.
The preference for being liberal in what you accept encouraged compatibility, but it could also reward vague specifications. Ambiguity leaves room for inconsistent implementations, and inconsistency becomes a security risk when systems make different assumptions. “Be forgiving” can quietly turn into “accept unexpected input,” which attackers love.
Shipping early interoperable code is valuable, yet it can bias outcomes toward the teams that can implement fastest—sometimes before the community has fully explored privacy, abuse, or long-term operational consequences. Later fixes are possible, but backwards compatibility makes some mistakes expensive to unwind.
Many early design choices assumed a smaller, more trusted community. As commercial incentives, state actors, and massive scale arrived, governance debates resurfaced: who gets to decide, how legitimacy is earned, and what “rough consensus” should mean when the stakes include censorship resistance, surveillance, and global critical infrastructure.
Postel didn’t “manage” the Internet with a grand plan. He helped it cohere by treating compatibility as a daily practice: write things down, invite others to try them, and keep the shared identifiers consistent. Modern product teams—especially those building platforms, APIs, or integrations—can borrow that mindset directly.
If two teams (or two companies) need to work together, don’t rely on tribal knowledge or “we’ll explain it on a call.” Document your interfaces: inputs, outputs, error cases, and constraints.
A simple rule: if it affects another system, it deserves a written spec. That spec can be lightweight, but it must be public to the people who depend on it.
Interoperability problems hide until you run real traffic across real implementations. Ship a draft spec, build a basic reference implementation, and invite partners to test while it’s still easy to change.
Shared specs and reference implementations reduce ambiguity, and they give everyone a concrete starting point instead of interpretation wars.
Compatibility isn’t a feeling; it’s something you can test.
Define success criteria (what “works together” means), then create conformance tests and compatibility goals that teams can run in CI. When partners can run the same tests, disagreements become actionable bugs rather than endless debates.
Stability requires a predictable path for change:
Postel’s practical lesson is simple: coordination scales when you reduce surprises—for both humans and machines.
One reason the IETF could converge was that ideas didn’t stay theoretical for long—they became runnable implementations that others could test. Modern teams can benefit from the same loop by reducing the friction between “we agree on an interface” and “two independent implementations interoperate.”
Platforms like Koder.ai are useful in that spirit: you can go from a written API sketch to a working web app (React), backend (Go + PostgreSQL), or mobile client (Flutter) through a chat-driven workflow, then iterate quickly with snapshots/rollback and source-code export. The tooling isn’t the standard—but it can make standards-like habits (clear contracts, fast prototyping, reproducible implementations) easier to practice consistently.
Interoperability wasn’t automatic because early networking was a patchwork of separate systems with different assumptions—address formats, message sizes, retry timers, error handling, and even incentives.
Without shared agreements, you get disconnected “islands” connected only by brittle, custom gateways.
Custom protocol bridges are expensive to build and maintain, easy to break as either side changes, and they often become chokepoints.
That creates vendor/operator lock-in because the party controlling the “translation layer” can dictate terms and slow competitors.
Because the “best” protocol doesn’t win if it can’t be implemented widely and consistently.
A slightly imperfect but broadly implementable standard can connect more networks than a technically elegant approach that only works inside one ecosystem.
He influenced outcomes through earned trust rather than formal authority: clear writing, patient coordination, and persistent follow-through.
He also handled the unglamorous work (editing, clarifying, nudging decisions, maintaining registries) that keeps independent implementers aligned.
An RFC (Request for Comments) is a publicly available memo describing an Internet protocol or operational practice.
Practically, it gives implementers a shared reference: formats, edge cases, and behaviors written down so different teams can build compatible systems.
“Rough consensus” means the group aims for broad agreement without requiring unanimity.
“Running code” means proposals should be proven by real implementations—ideally multiple independent ones—so the spec reflects what actually works on real networks.
Fragmentation would mean incompatible mini-networks with duplicated plumbing and constant translation.
The costs show up as:
The IETF provides an open process where anyone can read drafts, join discussions, and contribute evidence from implementation and operations.
Instead of hierarchy, influence tends to come from doing the work: writing drafts, testing ideas, responding to review, and improving clarity until systems interoperate.
IANA maintains shared registries (protocol numbers, port numbers, parameter codes, and parts of naming coordination) so independent implementations use the same values.
Without a single reference, you get collisions (same number, different meaning) and hard-to-debug incompatibilities that undermine otherwise “correct” standards.
Postel’s guideline—be strict in what you send, flexible in what you accept—helped early systems communicate despite uneven implementations.
But excessive tolerance can normalize malformed inputs and create security and interoperability bugs. A modern approach is compatibility with guardrails: validate strictly, document exceptions, log/limit noncompliance, and phase it out.