Network engineers do not need to become full-time coders to succeed–but some coding skills are really useful. In this episode of the Hedge, David Barrosso (you can find David’s github repositories here), Phill Simonds, and Russ White discuss which programming skills are useful for network engineers.
This post emphasizes the significance of network design for inference in AI, highlighting its distinct KPIs: Time to First Token (TTFT) and Inter-Token Latency (ITL). It discusses the prefill and decode phases, their resource profiles, and the challenges of KV cache management in multi-tenant environments, stressing the impact of network congestion on user experience.
The post Inference patterns create unique network demands appeared first on /overlaid.
Every secure web gateway on the market works the same way: traffic matches a condition. A terminal action fires. Allow, Block, Isolate, Log. This model has been the foundation of network security for nearly 30 years, and it handles the common case well. But it has a ceiling, and customers with complex environments hit that ceiling regularly.
Earlier this year, we shared our vision to build a truly programmable SASE platform. We also outlined how the term programmability has become diluted by the security industry. Most vendors claim programmability because they have public APIs, Terraform providers, webhooks, and alerting. Cloudflare offers all of those things too, but that’s not enough. True programmability means running your own code — arbitrary logic that you wrote for your specific environment — inline in the policy evaluation path, at the moment a security decision is made.
Today, we’re excited to announce Cloudflare is bringing true programmability to Cloudflare Gateway and DLP (Data Loss Prevention) by integrating it with the entirety of our edge computing platform. We are releasing a new type of Gateway action, Forward, and custom validation functions, available to all Zero Trust plans. These capabilities allow you to use a Cloudflare Worker Continue reading
VoidZero's tools such as Vite, Vitest, Oxc, and Rolldown — bundled in one toolchain as Vite+ — have made frontend development faster, but building full-stack applications requires more than just a tooling stack. These applications need server routes, databases, local development environments, and a fast and easy way to deploy ideas to production.
We’re excited to open-source three new products that bring server routing, typed data access, and Cloudflare deployment into a unified Vite workflow.
The CLI deploys apps built with the SDK to the Platform. All three products are open-sourced as a single JavaScript package and Vite plugin that you can install via npm install void. With Void, you can build your server and client together, carry types from your database to the UI, and let Void automatically provision the Cloudflare resources that your app uses.
We originally set out to build a single, private platform for all users to deploy apps to. After VoidZero joined Cloudflare, we Continue reading
Optimizing your site for AI is of little use if AI can't find it. The answer to someone's question may already be on your website: the installation guide you spent a week writing, or a first-hand account of using a product, with the details that make the difference for whether they buy it. As more people turn to AI for help, you want those systems to find your work, represent it accurately, and send interested people your way. You also want control over how they access your site.
Cloudflare and OpenAI launched a research pilot in July 2026 with those interests in mind. We wanted to find out whether signals from Cloudflare’s network could help ChatGPT users discover new content more efficiently.
Today, we’re sharing early results. So far, the answer is a resounding yes: the pilot has brought previously unknown pages into OpenAI’s search index, giving ChatGPT more sources to draw on to help people find relevant, timely information. Along the way, we’ve learned more about what makes a page worth discovering and how AI systems use the web.
The web is full of specifics. Someone fixing a washing machine needs the manual for Continue reading
So far, our playbooks have been fairly simple. Each task runs once, on every device, every time we run the playbook. That's fine for basic tasks, but as your playbooks grow, you'll want more control over how and when tasks run.
In this post, we'll look at three features that give you that control. Loops let you run the same task multiple times, once for each item in a list. Conditionals let you run a task only when a certain condition is true, such as when a variable is defined or a device is running a specific software version. And handlers let you run a task only when another task has made a change, which is perfect for things like saving the config.
We've used VLANs a lot in the previous posts, so for this post, we'll move on to something different and configure NTP and syslog instead. These are things almost every network needs, and they're a good fit for showing how loops, conditionals, and handlers work.
Before we start, let's take a quick look at where our project is at. We've added and changed quite a few files over the last few posts, so it's easy Continue reading
So far, most of what we've done has been about making changes, such as creating VLANs and saving the config. But a lot of day-to-day network work can be also about getting information from devices such as checking software versions, finding serial numbers, looking at interface status, or just running a quick show command across a group of switches.
In this post, we'll look at three ways to do that. First, we'll cover ad-hoc commands, which let you run a single task against your devices straight from the command line, without writing a playbook. Then, we'll look at facts, which is how Ansible collects information about a device, such as its hostname, model, and software version. You may have noticed that we've been setting gather_facts: false in every playbook so far, and we'll finally see why.
Finally, we'll go back to register and debug, which we briefly used in our very first playbook, and look at how to save the output of a task and use it in a more useful way.
So far, every time we wanted Ansible to do something, we wrote a playbook. But sometimes you just want to run a quick task, like Continue reading
Up until now, we've been storing the username and password for our switches in plain text. I mentioned a couple of times that this isn't a good idea, and now it's time to fix it.
Storing passwords in plain text might be fine in a lab, but in a real network, it's a big problem. Anyone who has access to your project directory can open the file and see the credentials for every device. And once you start storing your playbooks in Git, which you should, those passwords end up in your repository history as well, where they can stay long after you've removed them from the file.
Vault is a feature built into Ansible that lets you encrypt sensitive data, such as passwords, so it can't be read without a vault password. The best part is that Ansible decrypts it automatically when you run a playbook, so your playbooks don't need to change at all.
In this chapter, we'll encrypt the credentials for our switches, look at how to run playbooks with encrypted files, and cover a few different ways to work with Vault day to day.
We're continuing from where we left off in the Continue reading
In the previous chapter, we created inventory groups and moved the connection settings into the cisco group, so we only had to define them once. That works fine for now, but as your network grows, the inventory file can quickly get long and hard to manage, especially once you start adding more variables for each group and device.
We also have the VLANs hardcoded in the playbook. Right now, every switch gets the same four VLANs. But in a real network, you'll probably want different VLANs on the core switches and the access switches, and maybe even a specific VLAN on just one switch. Creating a separate playbook for each case isn't a good idea.
In this chapter, we'll look at how to organise the inventory and variables properly using group_vars and host_vars. We'll move the VLANs out of the playbook and into variables, so the same playbook can create different VLANs on different switches. We'll also look at how Ansible decides which variable to use when the same variable is defined in more than one place, and a few useful ways to target devices when running a playbook.
At the moment, our connection Continue reading
So far, we've only used Ansible to run show commands, which is a great way to get started because there's no risk of breaking anything. But at some point, you'll want to use Ansible to actually make changes, and that's what this chapter is all about.
We'll start small by creating a single VLAN on a single switch. From there, we'll create multiple VLANs, then run the same playbook against more devices, and slowly build on it until we're managing different VLANs on different switches. Each step introduces something new, so by the end of the chapter, you'll have covered a lot of the core Ansible concepts without even noticing.
Since we're working with VLANs, you'll need switches in your lab. If you're using Cisco IOS like me, make sure you're using the Layer 2 image rather than the router image. To keep things simple, I'll start with a single switch called s1, and we'll add more devices later in the chapter.
As always, please make sure you're running this in a lab and not on production devices. We're about to start making changes, so it's a good time to be extra careful.
Since we're working with Continue reading
YAML is a plain text format used to store and organize data. It's designed to be easy for humans to read and write, which is one of the main reasons Ansible uses it. The name originally stood for "Yet Another Markup Language", but it was later changed to "YAML Ain't Markup Language" to make it clear that it's meant for data, not documents.
In Ansible, almost everything you write is in YAML, including playbooks, inventory files, and variables. You've already seen two YAML files in the previous chapter, the inventory and the playbook.
If you've used Containerlab or Netlab, you've already worked with YAML, since their topology files are written in YAML too. It's also used by many other tools such as Docker Compose and Kubernetes, so learning it now will help you well beyond Ansible.
Here's a simple example of what YAML looks like.
hostname: r1
mgmt_ip: 192.168.202.101
ntp_servers:
- 10.10.10.10
- 10.10.10.11
Even if you've never seen YAML before, you can probably tell what this means. We have a device called r1, its management IP, and a list of two NTP servers.
YAML is simple, but it's also Continue reading
Before we install anything or write our first playbook, I want to spend a bit of time on why network automation matters and why Ansible is a good place to start. If you already know why you're here, feel free to skim this chapter, but I think it's worth understanding the problem before jumping into the tool.
For most of us, managing a network looks something like this. You open a terminal, SSH into a device, run a few show commands, paste in some config from a text file, verify it, save it, and move on to the next device. Repeat that for as many devices as you need to change.
There's nothing wrong with this approach when you're dealing with a handful of devices. I've done it for years, and so have most network engineers. The problems start when the network grows.
Imagine you need to change the NTP servers on 200 switches or configure Radius authentication on hundreds of devices. Doing that manually means logging into each switch, removing the old servers, adding the new ones, and saving the config. Even if each device only takes two minutes, that's almost seven hours Continue reading
My initial “configuring Arista cEOS with Netmiko or Ansible” test was a bit biased. netlab generates the final configuration snippets in both cases (due to Ansible FUBARs we had to deal with), but then Netmiko just sends the configuration commands to the switch (after entering configuration mode), while the Ansible eos_config module executes show running, identifies the difference, and sends only the changes to the device.
While that use case is highly relevant (after all, we’re configuring network devices ;) I really should have done an apples-to-apples comparison, and FRRouting virtual machines are the ideal playground.
Following reported strikes on Yandex data centers, claims circulated on the Internet that Russian bot farms and influence operations had been knocked offline. HTTP traffic charts showed steep drops, fueling speculation that the infrastructure damage had stopped these malicious actors. However, aggregate traffic metrics can easily mislead. There are two autonomous system numbers (ASNs) associated with Yandex: AS13238 is used by Yandex’s search engine, while AS200350 runs its cloud services.
Using Cloudflare Radar and Bot Management data, we analyzed how these two ASNs were affected — and while both saw drops in traffic, they saw differing impact.
While malicious traffic may originate from a particular provider, it does not necessarily tell us who is responsible for the traffic. Understanding why the strikes had little lasting effect on malicious traffic requires analyzing request behavior, rather than just overall traffic patterns.
Hyperdrive support for MySQL is now generally available (GA). Hyperdrive, Cloudflare’s database connection pooler for Workers, initially only supported Postgres. Since we announced the beta for MySQL protocol support last year, we have been working on making our MySQL handling as reliable as our Postgres support.
We’ve learned some things from building and running a MySQL connection pooler on Cloudflare’s network. It turns out that the difference between beta and GA is just 20 bug fixes in a trenchcoat.
During the beta, our goal was to validate that real-world customer usage hit our production availability target of 99.99%. We knew there were gaps in our reliability since we track how often client connections from a Worker end in an error related to Hyperdrive. In addition, we had feedback from customers in the beta that led to the discovery of a rare and subtle bug in our production environment. To convey the complexity of this particular bug, we first need to explain how Hyperdrive works.
Hyperdrive is a distributed database connection pooler that connects Cloudflare Workers to SQL databases. Hyperdrive holds warm SQL connections open on our global network and shares these connections across many Worker requests. Continue reading
Now that we know what we need to make layer-3 services (BGP-free core transporting IPv4 and IPv6 traffic) work with SRv6, let’s go through the steps needed to configure them on Junos, continuing from the baseline SRv6 with IS-IS configuration (and again relying on the excellent SRv6 Micro-SID (uSID) Basics article1 by Krzysztof Szarkowicz).
In the BGP-Free Network Core with SRv6, we identified the components we need (assuming IBGP+IGP design):