Running the Azure CLI in a Container

Like perhaps some readers, I am quite particular about what gets installed on my systems. I try to keep my systems as “clean” as possible, doing my best to avoid tools that have an extensive list of dependencies that must be installed and updated. Where that isn’t possible—such as with the Azure CLI, which has a massive number of Python modules that are required in order for the tool to function—I will use various isolation mechanisms. For the Azure CLI, that’s typically been a Python virtual environment. Somewhat recently, though, I had an idea to try using a container. In this post, I’ll share what worked and what did not work when trying to run the Azure CLI in a container.

First, though, a disclaimer: I am not an Azure expert, nor am I a Python expert. I know enough to get by. If I share something here that’s incorrect, please contact me and constructively show me my errors so that I can fix them.

Before I started down this path, I was sure this would be a slam dunk. I mean, this is what containers are for, right? If you do some web searches for running the Azure CLI Continue reading

Packet trimming Deep Dive – Part IV

Receive Network Processing Unit (Rx NPU)

Figure 9-4 illustrates a simplified receive-side processing pipeline, starting from the moment a Packet Header Vector (PHV), constructed by the Rx IFG, is delivered to the Receive Network Processing Unit (Rx NPU).

When the PHV arrives at the Rx NPU, it is dispatched to one of the Run-to-Completion (RTC) cores in the Packet Processing Array (PPA). Each RTC core processes the packet within a single execution context, allowing parsing, classification, lookup, and queuing decisions to be resolved without intermediate handoffs between processing stages.

The first task of the RTC parser is to perform deep inspection of the packet headers. While the Rx IFG has already extracted basic Layer-2 and Layer-3 information, the RTC parser determines whether the packet is tunneled and whether the switch itself is the tunnel termination point. To demonstrate this behavior, consider a VXLAN-encapsulated packet. The outer Ethernet and IP headers are used to forward the packet through the underlay network. If the outer destination IP address matches one of the local switch IP addresses, the device identifies itself as the tunnel endpoint. The tunneling protocol is recognized by examining the UDP header, where destination port 4789 indicates VXLAN. After the Continue reading

Modernizing with agile SASE: a Cloudflare One blog takeover

Return to office has stalled for many, and the “new normal” for what the corporate network means is constantly changing.  In 2026, your office may be a coffee shop, your workforce includes autonomous AI agents, and your perimeter is wherever the Internet reaches. This shift has forced a fundamental change in how we think about security, moving us toward a critical new architecture: agile SASE.

For too long, organizations have struggled under a 'fragmentation penalty,' juggling a patchwork of legacy hardware and Virtual Private Network (VPN) concentrators. These tools don't just require massive upfront investment; they create a mountain of technical debt — the cumulative cost of maintaining thousands of conflicting firewall rules, manual patches, and aging hardware that can’t support AI-scale traffic.

First-generation SASE providers promised a cure, but often just moved the mess to the cloud. By treating every data center as an isolated island, they’ve replaced hardware silos with operational silos. The result isn't a lack of visibility, but a lack of actionability: plenty of data, but no single way to enforce a consistent policy across a borderless enterprise.

Our customers have told us they need  an agile and composable platform. This week, we are announcing Continue reading

Beyond the blank slate: how Cloudflare accelerates your Zero Trust journey

In the world of cybersecurity, "starting from scratch" is a double-edged sword. On one hand, you have a clean slate; on the other, you face a mountain of configurations, best practices, and potential "gotchas."

While Cloudflare One has been often cited as one of the easiest-to-use SASE platforms, there is no magic without proper configuration. And while Cloudflare has been striving to simplify complex networking concepts by creating products such as Cloudflare WAN, Magic Transit, and Cloudflare Network Firewall, which simplify and reduce the typical complexity associated with deploying comparable functions from other vendors, the breadth of capabilities provided by Cloudflare One require creation of best-practice policies and templates to achieve the most optimal outcomes.

To make it easy to start taking advantage of Cloudflare’s powerful SASE platform, we have developed a method that ensures customers get the right configuration quickly and easily. We call it Project Helix. 

In this post, we’ll dig into the problem of getting the correct customization, and how we built Project Helix to make it simple. That means our customers have access to the most powerful SASE platform out there — and the easiest to onboard.

The complexity barrier: Why Continue reading

The truly programmable SASE platform

Every organization approaches security through a unique lens, shaped by their tooling, requirements, and history. No two environments look the same, and none stay static for long. We believe the platforms that protect them shouldn't be static either.

Cloudflare built our global network to be programmable by design, so we can help organizations unlock this flexibility and freedom. In this post, we’ll go deeper into what programmability means, and how Cloudflare One, our SASE platform, helps customers architect their security and networking with our building blocks to meet their unique and custom needs.

What programmability actually means

The term programmability has become diluted by the industry. Most security vendors claim programmability because they have public APIs, documented Terraform providers, webhooks, and alerting. That’s great, and Cloudflare offers all of those things too.

These foundational capabilities provide customization, infrastructure-as-code, and security operations automation, but they're table stakes. With traditional programmability, you can configure a webhook to send an alert to Slack when a policy triggers.

But the true value of programmability is something different. It is the ability to intercept a security event, enrich it with external context, and act on it in real time. Say a user attempts to Continue reading

Packet Trimming Deep Dive – Part III

Virtual Output Queue (VOQ)


The Silicon One VOQ Architecture

Instead of using dedicated deep interface buffers for packet queuing, Cisco Silicon One utilizes a Centralized Shared Memory architecture paired with a logical Virtual Output Queue (VOQ) mechanism. Because the VOQ concept is implemented within the Ingress (Rx) NPU entity, this queuing stage occurs after the initial ingress lookups but before the packet is switched across the internal fabric to the egress.

The VOQ model turns the traditional egress queuing model, where packets wait for serialization in a hardware buffer on the specific egress interface, upside down. While a VOQ is physically located on the ingress NPU, its ability to send traffic is controlled by the state of a small hardware Output Queue (OQ) on the egress interface.


Priority Mapping and Default State

As shown in Figure 9-3, a QoS policy can be created where a packet received on interface gi1/0/1 is assigned to Traffic Class 6 if the DSCP bits are set to EF (Expedited Forwarding). This configuration instantiates a VOQ specifically for that traffic class. In this hierarchy:

TC 7 (Control Plane/CS6): Mapped to OQ 1, the highest Strict Priority (Level 1).

TC 6 (DSCP-TRIMMED/EF): Mapped to OQ 2, Continue reading

Technology Short Take 191

Welcome to Technology Short Take #191! This is my semi-regular collection of links related to technology disciplines, including networking, security, cloud computing, storage, and programming/development. I hope that I’ve managed to curate an interesting and useful set of links for readers. Enjoy!

Networking

Security

Lab: More Complex EVPN/VXLAN Bridging Scenario

In the first EVPN/VXLAN lab, we added the EVPN control plane to bridging over VXLAN. Now, let’s try out a more complex scenario: several EVPN MAC-VRFs mapped to different VLAN segments on individual PE-devices.

Explore the lab exercise

You can run the lab on your own netlab-enabled infrastructure (more details), but also within a free GitHub Codespace or even on your Apple-silicon Mac (installation, using Arista cEOS container, using VXLAN/EVPN labs).

Toxic combinations: when small signals add up to a security incident

At 3 AM, a single IP requested a login page. Harmless. But then, across several hosts and paths, the same source began appending ?debug=true — the sign of an attacker probing the environment to assess the technology stack and plan a breach.

Minor misconfigurations, overlooked firewall events, or request anomalies feel harmless on their own. But when these small signals converge, they can explode into security incidents known as “toxic combinations.” These are exploits where an attacker discovers and compounds many minor issues — such as a debug flag left on a web application or an unauthenticated application path — to breach systems or exfiltrate data.

Cloudflare’s network observes requests to your stack, and as a result, has the data to identify these toxic combinations as they form. In this post, we’ll show you how we surface these signals from our application security data. We’ll go over the most common types of toxic combinations and the dangerous vulnerabilities they present. We will also provide details on how you can use this intelligence to identify and address weaknesses in your stack. 

How we define toxic combinations

You could define a "toxic combination" in a few different ways, but here Continue reading

We deserve a better streams API for JavaScript

Handling data in streams is fundamental to how we build applications. To make streaming work everywhere, the WHATWG Streams Standard (informally known as "Web streams") was designed to establish a common API to work across browsers and servers. It shipped in browsers, was adopted by Cloudflare Workers, Node.js, Deno, and Bun, and became the foundation for APIs like fetch(). It's a significant undertaking, and the people who designed it were solving hard problems with the constraints and tools they had at the time.

But after years of building on Web streams — implementing them in both Node.js and Cloudflare Workers, debugging production issues for customers and runtimes, and helping developers work through far too many common pitfalls — I've come to believe that the standard API has fundamental usability and performance issues that cannot be fixed easily with incremental improvements alone. The problems aren't bugs; they're consequences of design decisions that may have made sense a decade ago, but don't align with how JavaScript developers write code today.

This post explores some of the fundamental issues I see with Web streams and presents an alternative approach built around JavaScript language primitives that demonstrate something better is possible. 

Continue reading

The most-seen UI on the Internet? Redesigning Turnstile and Challenge Pages

You've seen it. Maybe you didn't register it consciously, but you've seen it. That little widget asking you to verify you're human. That full-page security check before accessing a website. If you've spent any time on the Internet, you've encountered Cloudflare's Turnstile widget or Challenge Pages — likely more times than you can count.

The Turnstile widget – a familiar sight across millions of websites

When we say that a large portion of the Internet sits behind Cloudflare, we mean it. Our Turnstile widget and Challenge Pages are served 7.67 billion times every single day. That's not a typo. Billions. This might just be the most-seen user interface on the Internet.

And that comes with enormous responsibility.

Designing a product with billions of eyeballs on it isn't just challenging — it requires a fundamentally different approach. Every pixel, every word, every interaction has to work for someone's grandmother in rural Japan, a teenager in São Paulo, a visually impaired developer in Berlin, and a busy executive in Lagos. All at the same time. In moments of frustration.

Today we’re sharing the story of how we redesigned Turnstile and Challenge Pages. It's a story told in three parts, by three Continue reading

Bringing more transparency to post-quantum usage, encrypted messaging, and routing security

Cloudflare Radar already offers a wide array of security insights — from application and network layer attacks, to malicious email messages, to digital certificates and Internet routing.

And today we’re introducing even more. We are launching several new security-related data sets and tools on Radar: 

  • We are extending our post-quantum (PQ) monitoring beyond the client side to now include origin-facing connections. We have also released a new tool to help you check any website's post-quantum encryption compatibility. 

  • A new Key Transparency section on Radar provides a public dashboard showing the real-time verification status of Key Transparency Logs for end-to-end encrypted messaging services like WhatsApp, showing when each log was last signed and verified by Cloudflare's Auditor. The page serves as a transparent interface where anyone can monitor the integrity of public key distribution and access the API to independently validate our Auditor’s proofs. 

  • Routing Security insights continue to expand with the addition of global, country, and network-level information about the deployment of ASPA, an emerging standard that can help detect and prevent BGP route leaks. 

Measuring origin post-quantum support

Since April 2024, we have tracked the aggregate growth of client support for post-quantum encryption on Cloudflare Continue reading

ASPA: making Internet routing more secure

Internet traffic relies on the Border Gateway Protocol (BGP) to find its way between networks. However, this traffic can sometimes be misdirected due to configuration errors or malicious actions. When traffic is routed through networks it was not intended to pass through, it is known as a route leak. We have written on our blog multiple times about BGP route leaks and the impact they have on Internet routing, and a few times we have even alluded to a future of path verification in BGP. 

While the network community has made significant progress in verifying the final destination of Internet traffic, securing the actual path it takes to get there remains a key challenge for maintaining a reliable Internet. To address this, the industry is adopting a new cryptographic standard called ASPA (Autonomous System Provider Authorization), which is designed to validate the entire path of network traffic and prevent route leaks.

To help the community track the rollout of this standard, Cloudflare Radar has introduced a new ASPA deployment monitoring feature. This view allows users to observe ASPA adoption trends over time across the five Regional Internet Registries (RIRs), and view ASPA records and changes over time Continue reading

Worth Reading 022626


The current debate on the existence of an “AI bubble” centers on a single question: is the current high level of investment into AI data centers a massive misallocation of capital or the key to future economic growth?

 


The more I have thought about it, the more convinced I am that the very technological advancements that make my life easier — the most recent being artificial intelligence — actually contribute to a busier, more overwhelming life.

 


Using hot water to cool supercomputers? Nvidia and others are doing it. It’s liquid cooling minus the water chillers.

 


New research shows that these claims aren’t true in all cases, particularly when account recovery is in place or password managers are set to share vaults or organize users into groups.

 


Every employer knows to conduct background checks. However, conducting background checks on IT professionals requires an extra layer of verification, given the privileged access they typically have to IT systems and tools.

Configuring 6PE Route Reflector on Cisco IOS

Imagine you want to deploy a BGP route reflector for MPLS 6PE or L3VPN service. Both services run over MPLS LSPs, use IPv4 BGP sessions, and use IPv4 next hops for BGP routes. There’s absolutely no reason to need IPv6 routing on a node that handles solely the control-plane activity (it never appears as a BGP next hop anywhere), right? Cisco IOS disagrees, as I discovered when running route reflector integration tests for netlab 6PE and (MPLS) L3VPN functionality.

Most platforms failed those tests because we forgot to configure route-reflector-clients in labeled IPv6 and VPNv4/VPNv6 address families1. That was easy to fix, but the IOS-based devices were still failing the tests, with nothing in the toolchain ever complaining about configuration problems.

Read more …
1 2 3 … 3,849