Last Friday, NetFoundry’s CEO Galeal Zino appeared on the weekly live YouTube show Super Cyber Friday, hosted by tech journalist David Spark.
Super Cyber Friday is about cybersecurity practitioners and vendors, and every episode has a title that follows a “Hacking [Topic]” format. This particular episode’s title is Hacking Microsegmentation for Machine Workloads, and features:
- Galeal Zino, NetFoundry CEO (and my boss’ boss, and therefore the best damned skip-level in the world)
- Howard Holton, Founder and Principal Counsel at Phronia Counsel, an independent technology analyst and advisory firm
If you’re wondering what microsegmentation is, here’s the short version:
Microsegmentation is the practice of carving your network into tiny zones so that when something gets compromised (and something will), the damage stays in one small room instead of spreading through the whole house.
Everyone agrees it’s a good idea, almost nobody enjoys doing it, and few actually do it. It’s the brushing and flossing of cybersecurity.
Before the notes, some disclosure
You should know:
- I do developer advocacy work at NetFoundry in exchange for money, health insurance, and to convince people I’m more than just an accordion-playing reprobate.
- Once again, Galeal is my boss’s boss. And he’s a great boss’ boss!
- NetFoundry sponsored this episode.
Feel free to apply the appropriate amount of skepticism to this writeup, but keep in mind that this episode features both a CEO who builds security stuff with an analyst who’s had to live with the results. The episode’s a little more blunt than your typical PR piece.
The tl;dr
C’mon, this article isn’t that long! But still, if you want a very quick summary, here it is…
| The old way | What machine workloads need | |
| What you segment by | IP addresses, subnets, CIDR blocks, VLANs | A cryptographic identity for every machine, plus attestation |
| Where enforcement happens | Firewalls and middleboxes at the edge | Inside the application, via an identity-driven overlay |
| How AI agents get treated | “It’s basically an employee” or “It’s basically an app” | As a non-human actor with explicitly bounded access |
| What failure looks like | Firewall surgery, configuration bloat, shelfware | A contained blast radius |
| What the board says | “We better never get hacked.” | “How bad will it be when we get hacked?” |
“Early microsegmentation sucked so bad…”
Howard set the tone in the first minute, when David asked for his microsegmentation pet peeve (0:08):
“Early microsegmentation sucked so bad that it’s hard to get people to listen when you talk about microsegmentation.”
For the record, Howard is a big microsegmentation fan. What drives him (and us at NetFoundry too) up the wall is the feedback he hears most often: “Nope, we did that before, we’re not doing it again.” People tell him it was too complicated and a waste of money. He hates that feedback because, in his words, “it’s just wrong.”
Later in the show (7:25), he explained how early rollouts earned that reputation. Teams would get frustrated during the discovery stage, put some segments in place, and then cause an outage by blocking something that only ran once every 30 days and that nobody had planned for. After that happened a few times, they’d shelf whatever microsegmentation tool they were using. His summary: “Complexity always bites you in the ass.”
If you’ve ever been anywhere near a rollout like that, you probably just winced. The problem wasn’t the idea. Least privilege and blast-radius reduction are good ideas! The problem was that vendors tried to implement them with the tools that just happened to be conveniently lying around: IP addresses, subnets, VLANs, and firewalls.
When an audience member asked whether application-level or network-level microsegmentation is more effective, Galeal didn’t mince words (9:05):
“Network-level is DOA: dead on arrival. It’s an oxymoron to begin with… It’s spilled milk, and you can’t put it back in the bottle. If you’re going to try and use IP addresses, VLANs, and firewalls to do ‘microseg,’ good luck to you. It’s not going to happen.”
That’s coming from someone who’s been doing network engineering for 30 years. Here’s the core problem, especially for machines: an IP address tells you where something is, not what it is. In a world of containers, autoscaling, and serverless functions, the IP address your billing service has this morning might belong to something completely different by the time lunch rolls around. Writing security policy against IP addresses is like keeping track of your friends by remembering which seats they sat in the last time you all went to the movies. Or, as Galeal put it later in the show (35:10), “IP addresses are not identities.”
Howard then described what happens when you try to brute-force it anyway (10:03):
“Microsegmentation and segmentation are not the same thing… If you’re like, ‘Well, I’m going to create 437 subnets in my network and I’m going to create 300 VLANs and I’m going to turn on host-based firewalls,’ you’ve just created a nightmare that no one is ever going to be able to manage after you. And you have failed job number one, which is make sure that the next person can be as successful as you are.”
“Make sure that the next person can be as successful as you are.” I want that on a poster, and not just for network engineers. It applies to code, documentation, and pretty much anything you build that someone else will inherit.
And if you try to do it the classic way regardless, making your firewalls enforce all that traffic between your services? According to Galeal (29:48), that’s the first lesson you’ll learn: “You will melt your firewalls.”
Credentials aren’t identity
My favorite moment in the episode came from an audience question. Sierra Montgomery asked (11:05):
“If a compromised workload acquires valid credentials and begins behaving like a legitimate service, what signal does your microsegmentation architecture use to distinguish legitimate machine-to-machine communication from lateral movement?”
Galeal’s answer was one word: Attestation. His reasoning: a credential doesn’t prove whether Howard, David, or an AI agent should have it. Credentials, he said, are “necessary but not sufficient.”
Explaining bearer tokens is something that goes back to my first article for Auth0, which was also my “take-home assignment” in the job interview process. The concept always needed the most careful explaining, even though the name told you everything: whoever bears the token gets the access. The token doesn’t know or care who’s holding it. It’s more like cash than a credit card.
That’s fine as long as you know where the token is. The trouble starts when you don’t. A credential proves that something possesses a secret. It doesn’t prove that the thing should have that secret, and it says nothing about whether the machine presenting it is in the state it’s supposed to be in. Attestation fills that gap: it’s verifiable evidence that the workload is what it claims to be, and that it’s running where and how it’s supposed to.
Take the pwning like a champ
At a DEF CON party a long time ago, a few friends and I came up with a joke talk title for the following year’s edition of the conference: “Security is for lightweights. Take the pwning like a champ.”
But behind the joke was an important idea: every boxer gets hit. What makes a champ isn’t never getting punched; it’s being able to take the punch and stay on your feet. Security works the same way. Sooner or later, one of your credentials is going to end up in the wrong hands, whether it’s through a phished password, a leaked API key, or a token that got copied out of a log file. Back then, planning on getting pwned was a punchline. These days, it’s a design principle, and it’s exactly where Galeal starts.
The DEF CON joke came to my mind when an audience member asked how a platform can alert on a compromised token moving laterally (16:06). Galeal’s answer was in the spirit of “Take the pwning like a champ”: Assume that tokens will be compromised, and design your system so that a token by itself doesn’t grant access.
If your architecture opens the door and grants network reachability before it verifies identity, an ill-gotten token can be a starting point to explore your network. The “Take the pwning like a champ” approach that NetFoundry takes verifies identity first and uses policies to spells out which identities can talk to which services. A stolen token doesn’t open any new doors, because the path the attacker wants isn’t accessible to them.
AI agents are chaos monkeys nobody scheduled
History time! If you were a developer around the time the iPad came out, you might remember Chaos Monkey, Netflix’s tool designed to randomly shut down servers in production. The idea behind it could be summarized as “The random shutdowns will continue until resiliency improves”. Netflix’s dev teams were forced to build in such a way that their systems would survive failure. It’s a brilliant (if sadistic) idea, and it works because Netflix chose to unleash it deliberately, with rules.
This isn’t all too different from a pattern Galeal described (28:56): taking an AI agent and saying, “Hey, cool. Here’s some API keys. Here’s the internet. Here’s some enterprise resources. Go do something useful.”
Howard’s response: “I see that like 40 times a week.” That’s a chaos monkey too, except nobody scheduled it, nobody wrote the rules, and it will explain its reasoning very confidently afterward.
My last job prior to my current Developer Advocate gig at NetFoundry was optimizing an MCP server, so this isn’t a hand-wavey “some customer has this issue” thing to me. Every tool or function you expose through an MCP server is something an agent can decide to call, whenever it wants, for reasons you didn’t anticipate. Its network traffic doesn’t follow a script.
When an audience member asked how to segment an AI agent whose needed connections change with each task, Howard’s advice was (27:27):
“If you try to design something that is entirely flexible, what you’re going to end up with is opening yourself up for AI chaos in your network… If you do it the other way around and hope that your microsegmentation tool set is going to keep up with your AI, you’re basically saying, ‘I want microseg to follow my chaos monkey.’ Do it the other way around. Use microsegmentation to restrict the chaos monkey.”
Galeal’s answer to the same question (26:43) supplies the other half: The old bag of tricks isn’t going to work on agentic flows. Treat agents as identities, define a graph of what each one can talk to and under what conditions, and have the visibility and enforcement to make sure they stay on that graph.
That’s the right mental model. An AI agent isn’t a human employee sitting behind your SSO portal, and it isn’t a cron job that does the same thing at the same time every night. It’s a whole new thing.
As Howard put it later in the show, it isn’t another application, and it doesn’t act like a human either. It needs boundaries defined up front, including things like:
- A specific identity,
- ashort list of things it’s allowed to reach, and i
- solation that travels with it whether it’s running in AWS, on bare metal, or in an OT facility.
What this looks like if you write code
Time for me to put my work hat on for a minute. The table above mentions “an identity-driven overlay” enforced “inside the application,” which is a mouthful, so here’s what it means in practice.
OpenZiti is the open source zero trust networking platform that NetFoundry builds, and one of the things it lets you do is embed zero trust directly into your application with an SDK. Your app gets its own cryptographic identity, and it can only reach the services that policy says it’s allowed to reach. On the other side, services don’t need open inbound ports at all, so there’s nothing sitting on the network for an attacker to scan, probe, or point a stolen token at.
Galeal’s “kill switch” (more on that below) gets pretty concrete here too: if an identity is compromised, you revoke it or change the policy, and its paths go away. No firewall surgery required.
If you want to try it yourself, the docs and quickstarts are at openziti.io.
What do you tell the board?
Near the end, David read an audience question: Which metric best shows leadership that microsegmentation is working? Galeal boiled his answer down to three questions (39:11):
- The graph: Can you answer the question “What identity can talk to what identity, according to what policy?” (Note that he said identity, not IP address.)
- The kill switch: When something unexpected happens, where’s the kill switch that lets you deal with it without compromising uptime, human safety, or business continuity?
- Centralized governance: How much of all this can you see and govern from one place, instead of going to a bunch of different environments and firewalls?
Then Howard put on his gloves (41:27): “I couldn’t disagree more.” Speaking as a CISO, he said:
“What my board said 10, 15 years ago was, ‘We better never get hacked.’… Today they say, ‘How bad will it be?’ That is their question to me. That is the question they want me to answer in every board meeting they invite me to.”
My answer would be “Take the pwning like a champ”.
David pointed out that the two answers aren’t really in conflict: Galeal was describing what you measure for yourself and your security team, and Howard was describing what you tell the board. Galeal agreed. Howard then explained why the board version has to be so compressed (43:29):
“I get one slide as a CISO… I get like five minutes… I make that one slide tell them how I’m spending money to make it less bad than the last time they gave me money.”
Ah, the dreaded “You get one, and only one, slide” directive for board meeting presentations. Replace “board” with “VP of Engineering” or “whoever approves your budget,” and it’s still excellent advice.
My takeaway
If I had to boil the whole episode down to one idea, it wouldn’t be about AI, firewalls, or attestation. It would be Howard’s “job number one”: make sure the next person can be as successful as you are.
Galeal landed in the same place from a different direction. When David asked why he started NetFoundry (24:00), he said that after years of beating his head against walls like microsegmentation, he wanted to tilt the playing field so that the next person who has to solve these problems doesn’t have to.
That’s the real case against building microsegmentation out of subnets and VLANs. Even if you get it working, you’ve built something nobody else can understand, let alone maintain.
A policy that says “the billing service can talk to the orders database, and the AI agent can talk to these three APIs and nothing else” is something the next person can read, reason about, and change without breaking everything. And when some of the things doing the talking are AI agents that nobody can fully predict, that kind of clarity is what keeps the chaos monkey in its cage.
Go watch the episode, and if you’re a developer who wants to see what identity-first networking looks like from the inside, take OpenZiti for a test drive!
(And DHH also did it so LOUDLY. I can’t be the only one who’s noticed that late-career DHH is a lot like late-career Al Pacino, who seems to think that the most effective way to get a message across is by YELLING.)
