Repost: Layer-3-Only EVPN Behind the Scenes
After publishing the EVPN L3VPN lab-building instructions, I published a deep dive into EVPN and data-plane data structures. You might have missed it, as it was published in mid-August.
Impact of Verizon’s September 30 outage on Internet traffic
On Monday, September 30, customers on Verizon’s mobile network in multiple cities across the United States reported experiencing a loss of connectivity. Impacted phones showed “SOS” instead of the usual bar-based signal strength indicator, and customers complained of an inability to make or receive calls on their mobile devices.
AS6167 (CELLCO) is the autonomous system used by Verizon for its mobile network. To better understand how the outage impacted Internet traffic on Verizon’s network, we took a look at HTTP request volume from AS6167 independent of geography, as well as traffic from AS6167 in various cities that were reported to be the most significantly impacted.
Although initial reports of connectivity problems started around 09:00 ET (13:00 UTC), we didn’t see a noticeable change in request volume at an ASN level until about two hours later. Just before 12:00 ET (16:00 UTC), Verizon published a social media post acknowledging the problem, stating “We are aware of an issue impacting service for some customers. Our engineers are engaged and we are working quickly to identify and solve the issue.”
As the Cloudflare Radar graph below shows, a slight decline (-5%) in HTTP traffic as compared to traffic at the Continue reading
Connection coalescing breaks the Internet
Connection coalescing is the dumbest idea to ever reach RFC status. I can’t believe nobody stopped it before it got this far.
It breaks everything.
Thus starts my latest opinion post.
What is connection coalescing?
It’s specified in the RFC for HTTP/2 as connection reuse, but tl;dr: If the IP address of host A and B overlap, and host A presents a TLS cert that also includes B (via explicit CN/SAN or wildcard cert), then the client is allowed to send HTTP requests directed to B on the connection that was established to A.
Why did they do that?
To save roundtrips and TLS handshakes. It seems like a good idea if you don’t think about it too much.
Why does it break everything?
I’ll resist just yelling “layering violation”, because that’s not helpful. Instead I’ll be more concrete.
Performing connection coalescing is a client side (e.g. browser) decision. But it implicitly mandates a very strict server architecture. It assumes that ALL affected hostnames are configured exactly the same in many regards, and indeed that the HTTP server even has the config for all hostnames.
Concrete things that this breaks:
- The server can’t have a freestanding TLS termination layer, Continue reading
Tech Bytes: Security and Operational Benefits of Fortinet Unified SASE (Sponsored)
Secure Access Service Edge, or SASE, brings together networking and cloud-delivered security services. On today’s Tech Bytes podcast we with talk with sponsor Fortinet about Unified SASE; that is, where a single provider offers both the networking and cloud elements of the service. We discuss essential elements of Unified SASE, Fortinet’s notion of sovereign SASE,... Read more »New Day, New Role
I’m thrilled to announce that I’ve recently stepped into a new role as Solutions Architect at Sweetwater Technology Services! This opportunity marks a significant milestone in my career, allowing me to deepen my expertise and broaden my impact in designing and delivering IT solutions for clients across diverse sectors. What This Means In this role, …
The post New Day, New Role first appeared on StaticNAT.
Leadership vs Management
Leadership and management these two are often used interchangeably but are they interchangeable? Do we consider all managers to also be leaders and are all leaders managers? While the best managers will have traits of a good leader and visa-versa these two roles are not always synonymous. First thing we will want to do is […]AI for Network Engineers: Chapter 2 – Backpropagation Algorithm: Introduction
This chapter introduces the training model of a neural network based on the Backpropagation algorithm. The goal is to provide a clear and solid understanding of the process without delving deeply into the mathematical formulas, while still explaining the fundamental operations of the involved functions. The chapter also briefly explains why, and in which phases the training job generates traffic to the network, and why lossless packet transport is required. The Backpropagation algorithm is composed of two phases: the Forward pass (computation phase) and the Backward pass (adjustment and communication phase).
In the Forward pass, neurons in the first hidden layer calculate the weighted sum of input parameters received from the input layer, which is then passed to the neuron's activation function. Note that neurons in the input layer are not computational units; they simply pass the input variables to the connected neurons in the first hidden layer. The output from the activation function of a neuron is then used as input for the connected neurons in the next layer, whether it is another hidden layer or the output layer. The result of the activation function in the output layer represents the model's prediction, which is compared to the expected Continue reading
Wrapping up another Birthday Week celebration
2024 marks Cloudflare’s 14th birthday. Birthday Week each year is packed with major announcements and the release of innovative new offerings, all focused on giving back to our customers and the broader Internet community. Birthday Week has become a proud tradition at Cloudflare and our culture, to not just stay true to our mission, but to always stay close to our customers. We begin planning for this week of celebration earlier in the year and invite everyone at Cloudflare to participate.
Months before Birthday Week, we invited teams to submit ideas for what to announce. We were flooded with submissions, from proposals for implementing new standards to creating new products for developers. Our biggest challenge is finding space for it all in just one week — there is still so much to build. Good thing we have a birthday to celebrate each year, but we might need an extra day in Birthday Week next year!
In case you missed it, here’s everything we announced during 2024’s Birthday Week:
Monday
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What |
In a sentence… |
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Start auditing and controlling the AI models accessing your content |
Understand which AI-related bots and crawlers can access your website, and which content you choose to allow Continue reading |
IS-IS Labs: Configure IS-IS Routing for IPv4
In the first exercise in the IS-IS labs series, you’ll configure IS-IS routing for IPv4. The basic configuration is trivial, but you’ll also have to tweak the defaults that most vendors got wrong (we’ll discuss why those defaults are wrong in the next lab exercises).
I also tried to make the IS-IS labs more than just lab exercises. Each exercise includes a bit of background information or IS-IS theory; this one describes generic OSI addresses (NSAPs) and router addresses (NETs).
Consolidating WAN Backbone with EVPN
Recently I was exploring how to consolidate layer-2 & layer-3 connectivity across WAN backbone network. In this write I have covered (IP-Prefixes handling as EVPN Type 5 Routes) and in subsequent writeup I will cover E-LAN and E-Line use cases as well.
https://github.com/kashif-nawaz/Consolidating_WAN_Backbone_with_EVPN
Palo Alto App-ID – How Does It Work?
If you've ever worked with traditional Layer 4 firewalls, you might be familiar with configuring security policies based on TCP or UDP port numbers. For instance, to allow DNS, you'd create a policy for UDP/53, or for LDAP, a policy for TCP/389.
This approach is normal with firewalls like Cisco ASA. But it's 2024, and Next-Generation Firewalls (NGFWs) have become the standard, offering a more sophisticated way to manage security. Instead of relying solely on port numbers, NGFWs like those from Palo Alto Networks encourage defining security policies based on the actual applications termed 'App-ID'. For example, instead of specifying port numbers, a policy could simply be defined to allow 'DNS' and 'LDAP', focusing on the applications themselves.
Palo Alto App-ID Introduction
Okay, that sounds simple, so why continue reading you may ask? Well, while Palo Alto’s App-ID does work well most of the time, there are nuances that you need to understand. For applications like DNS, NTP, and LDAP, App-ID works very well. However, the most common applications involve SSL or web browsing, typically associated with ports 80 and 443.
Palo Alto provides App-IDs for both SSL and Web-Browsing (called ssl and web-browsing Continue reading
HN751: Top Tips for Building A CCIE-EI Lab
The Packet Pushers and guest Mason Reimert discuss strategies he’s using to prepare for the Cisco CCIE Enterprise Infrastructure lab exam. Mason shares practical tips for hands-on labbing for both established and emerging technologies like SD-WAN and SD-Access, resource management, virtualization tools, and automation. He also highlights the importance of understanding APIs, data formats, and... Read more »Expanding Cloudflare’s support for open source projects with Project Alexandria
At Cloudflare, we believe in the power of open source. It’s more than just code, it’s the spirit of collaboration, innovation, and shared knowledge that drives the Internet forward. Open source is the foundation upon which the Internet thrives, allowing developers and creators from around the world to contribute to a greater whole.
But oftentimes, open source maintainers struggle with the costs associated with running their projects and providing access to users all over the world. We’ve had the privilege of supporting incredible open source projects such as Git and the Linux Foundation through our open source program and learned first-hand about the places where Cloudflare can help the most.
Today, we're introducing a streamlined and expanded open source program: Project Alexandria. The ancient city of Alexandria is known for hosting a prolific library and a lighthouse that was one of the Seven Wonders of the Ancient World. The Lighthouse of Alexandria served as a beacon of culture and community, welcoming people from afar into the city. We think Alexandria is a great metaphor for the role open source projects play as a beacon for developers around the world and a source of knowledge that is core to making a Continue reading
Advancing cybersecurity: Cloudflare implements a new bug bounty VIP program as part of CISA Pledge commitment
As our digital world becomes increasingly more complex, the importance of cybersecurity grows ever more critical. As a result, Cloudflare is proud to promote our commitment to the Cybersecurity and Infrastructure Security Agency (CISA) ‘Secure by Design’ pledge. The commitment is built around seven security goals, aimed at enhancing the safety of our products and delivering the most secure solutions to our customers.
Cloudflare’s commitment to the CISA pledge reflects our dedication to transparency and accountability to our customers, and to cybersecurity best practices. Furthermore, Cloudflare is committed to being a trusted partner by sharing our strategies to ensure the highest priority is placed on safeguarding our customers’ security.
Bug bounty VIP program
Cloudflare has successfully managed a public Vulnerability Disclosure Program (VDP) for years; our belief is that collaboration is the cornerstone of effective cybersecurity. We are excited to announce a major milestone in our journey to meet Goal #5 of the pledge: our program will now include a bug bounty VIP program in conjunction with our bug bounty public program.
Continuous investment in maturing our bug bounty program is a vital tool for the success of any security organization. By encouraging broader participation in vulnerability testing, Continue reading
Empowering builders: introducing the Dev Alliance and Workers Launchpad Cohort #4
Today we’re announcing the Dev Starter Pack, an alliance of innovative tools for developers to get started with discounts and free services. We’re also excited to share an update on our Workers Launchpad Program.
Creating from the ground up often means spending countless hours piecing together the right development stack, navigating different pricing models, and managing growing costs — all of which can take your focus away from what truly matters: building your product and growing your business.
Introducing Dev Starter Pack: the tools you need to start building your startup
Hey! Dani Grant here, one of the first PMs at Cloudflare and co-founder of Jam.dev. Ten years ago (during 2014’s Birthday Week), Cloudflare launched Universal SSL, making SSL free on the Internet for the first time, and in one night doubling the size of the encrypted web.
I was a college student back then, and I immediately became enraptured by Cloudflare’s mission: helping build a better Internet. As part of this mission, Cloudflare has developed powerful tools typically accessible only to Internet giants, oftentimes offering them for free to developers and individuals alike. Heck yeah! I joined Cloudflare in January 2015, and 5 years after that, co-founded Continue reading
Network trends and natural language: Cloudflare Radar’s new Data Explorer & AI Assistant
Cloudflare Radar showcases global Internet traffic patterns, attack activity, and technology trends and insights. It is powered by data from Cloudflare's global network, as well as aggregated and anonymized data from Cloudflare's 1.1.1.1 public DNS Resolver, and is built on top of a rich, publicly accessible API. This API allows users to explore Radar data beyond the default set of visualizations, for example filtering by protocol, comparing metrics across multiple locations or autonomous systems, or examining trends over two different periods of time. However, not every user has the technical know-how to make a raw API query or process the JSON-formatted response.
Today, we are launching the Cloudflare Radar Data Explorer, which provides a simple Web-based interface to enable users to easily build more complex API queries, including comparisons and filters, and visualize the results. And as a complement to the Data Explorer, we are also launching an AI Assistant, which uses Cloudflare Workers AI to translate a user’s natural language statements or questions into the appropriate Radar API calls, the results of which are visualized in the Data Explorer. Below, we introduce the AI Assistant and Data Explorer, and also dig into how we Continue reading