N4N005: The Sort-of-Useful OSI Model
Network engineers should be familiar with the Open Systems Interconnection (OSI) model, a framework for understanding network communications. On today’s show, Ethan and Holly delve into each of the model’s seven layers to discuss their functions, associated protocols, and practical implications for modern networking. They also talk about how the OSI model is, in fact,... Read more »The “simple” 38 step journey to getting an RFC
The “simple” 38 step journey to getting an RFC
The Internet is built on the mutual understanding of network protocols and practices, and most of those protocols are defined using Request For Comments (RFC) or Best Common Practices (BCP) documents.
Worth Reading: Codespaces for Network Engineers
When I discovered GitHub Codespaces (thanks to a pointer by Roman Dodin), I did the absolute minimum of research to get netlab up and running in a container to enable Codespaces-based labs (BGP, IS-IS) and netlab examples.
However, if you want to know the behind-the-scenes details, you MUST read the Codespaces for Network Engineers and Educators deep dive by Julio Perez.
NAN080: Elevating Your Network Automation Skills and the DevNet Expert Track
Ongoing education and training is a constant in a networking career, especially if you want to advance. And certifications are a common path forward. On today’s episode, guest Andreas Baekdahl shares his journey from traditional networking to automation architect and certification instructor. Along the way, he’s had his share of challenges and failures, and he... Read more »D2DO259: See Deep Inside Public Cloud for Greater Visibility and Troubleshooting with ThousandEyes Cloud Insights (Sponsored)
Public cloud networks can be a bit of a black box when it comes to monitoring and troubleshooting. Today on Day Two DevOps we talk with sponsor Cisco ThousandEyes about its Cloud Insights tool, which aims to open that box so you can see exactly what’s going on in your cloud networks, identify problems, help... Read more »Is BGP PIC Edge an Oxymoron?
This blog post discusses an old arcane question that has been nagging me from the bottom of my Inbox for almost exactly four years. Please skip it if it sounds like Latin to you, but if you happen to be one of those readers who know what I’m talking about, I’d appreciate your comments.
Terminology first:
- Prefix Independent Convergence allows entries in the forwarding table to point to shared next hops (or next-hop groups), reducing the FIB update bottleneck when changing the next hop for a large number of prefixes (for example, when dealing with a core link failure). More details in the initial blog post and PIC applicability to fast reroute.
- PIC Edge (as defined by vendor marketing) is the ability to switch to a backup CE route advertised to a backup PE router before the network convergence is complete.
Here’s (in a nutshell) how PIC Edge is supposed to work:
From deals to DDoS: exploring Cyber Week 2024 Internet trends
In 2024, Thanksgiving (November 28), Black Friday (November 29), and Cyber Monday (December 2) significantly impacted Internet traffic, similar to trends seen in 2023 and previous years. This year, Thanksgiving in the US drove a 20% drop in daily traffic compared to the previous week, with a notable 33% dip at 15:45 ET. In contrast, Black Friday and Cyber Monday drove traffic spikes. But how global is this trend, and do attacks increase during Cyber Week?
At Cloudflare, we manage and protect a substantial amount of traffic for our customers, providing a unique vantage point to analyze traffic and attack patterns across the Internet. This perspective reveals insights like Cyber Monday being the busiest Internet traffic day of 2024 globally, followed by Black Friday, with patterns varying across countries. Notably, global HTTP request volume on Cyber Monday 2024 was 36% higher than 2023, with 5% of that traffic blocked as potential attacks.
For this analysis, we examined anonymized and aggregated HTTP requests and DNS queries across our network to uncover key patterns. Cyber Monday, December 2, was the day with peak traffic, and key findings for that day include:
Cloudflare processed a peak of 99.8 million HTTP requests per Continue reading
PP042: CISO Liability Insurance, A Seriously Dangerous Menu Hack, and more Security News
Our monthly news roundup discusses liability insurance for CISOs (if you are one, you should get it), serious intrusions of US telecom companies by Chinese state actors (according to the FBI), and a novel attack that leapt across multiple Wi-Fi networks. We also discuss significant vulnerabilities affecting Palo Alto Networks’ Expedition migration product, how fake... Read more »HS090: AI Regulations: What You Don’t Know CAN Hurt You!
This has been a big year for AI regulation, from the EU AI Act to the much hyped California SB1047, currently in limbo. With things bubbling along across the country, and at the federal level, and internationally, there’s a lot going on and IT folks should be keeping current and planning to meet a changing... Read more »
Bringing SWAG to Enterprise Campus Networking!
As client users, devices, and IoT continue to proliferate, the need for switching management and workload optimization across domains increases. Many sub-optimal and closed approaches have been designed in the past. Arista was founded to build the best software and hardware, equating to the highest performance and density in cloud/data centers, and now evolving to campus switches. In 2020, we introduced the smallest footprint of Arista CCS 750 and 720 series switches as a fitting example of the highest density and lowest footprint.
NB506: Billions Flow for US Chips; FCC Lets T-Mobile, SpaceX Make Phone Calls from Orbit
Take a Network Break! We’ve got a full menu for our post-Thanksgiving episode. We start with a host of critical CVEs affecting Veritas and a couple more for QNAP. Cisco announces EOL for two version of its ACI software, Verizon runs field trials for 1.6Tbps throughput in a single wavelength (with Ciena optical transceivers), and... Read more »netlab: Sample Cisco ASAv Topology
A happy netlab user asked for a sample Cisco ASAv topology that would include an inside and an outside router.
We don’t have anything similar in the netlab examples yet, so let’s build a simple topology with two routers, a firewall, and a few hosts.
However, we have to start with a few caveats:
How AI Chatbots Improve Network Configuration Management
Templating and Data Representation: Aspect of Network Automation using a tailor made AI Chatbot just to handle this scenario
In today’s exploration, we’ll dive into the fascinating world of automation frameworks and how different data formats work together to create powerful, maintainable solutions. Drawing from extensive hands-on experience, I’ll share insights into how XML, JSON, and YAML complement each other in modern automation landscapes.
The Three Pillars of Automation Data Handling
- Expression Through XML XML has long served as the backbone of structured data expression. Its verbose yet precise nature makes it particularly valuable for scenarios requiring strict schema validation and complex hierarchical relationships. Think of XML as the detailed blueprints of your automation architecture.
- Serialisation with JSON JSON has revolutionised data interchange in modern applications. Its lightweight structure and native compatibility with JavaScript have made it the de facto standard for API communications. Consider JSON as your data’s travel format – efficient, universally understood, and easy to process.
- Presentation via YAML YAML brings human-readability to configuration management. Its clean syntax and support for complex data structures make it ideal for writing and maintaining configuration files. Think of YAML as your user interface to data representation – intuitive, clean, and Continue reading
Example: Multi-AS netlab Topology
A few weeks ago, Urs Baumann posted a nice example illustrating the power of netlab: a 10-router topology running OSPF, IS-IS, and BGP:
He didn’t post the underlying topology file, so let’s create a simple topology to build something similar.
From Python to Go 005. Code Flow Control: Loops and Conditionals.
Hello my friend,
In the previous blog post we briefly touched on the conditionals, when we talked about looking for presence of some element in Python list or Go slice. So I thought, it would make sense to introduce now the key concept of the code flow control, which are conditionals and loops. These items are essential for any production code, so let’s see how it works.
Does Automation Come Last?
Surfing through the LinkedIn today I’ve found an interesting picture, which was attributed to Elon Musk and Twitter (or X, how is that called now):
I don’t if that is really related to Mr Musk and Twitter in any capacity, but thoughts it contains are quite important: your first remove all unnecessary steps and optimize everything you can, before you start any automation. That’s very true and in our network automation trainings we talk about how to optimize network operations processes to ensure that they are viable for automation. Join our network trainings to learn how to build viable automation:
We offer the following training programs in network automation for you:
Configuring the Cisco Aironet AP 1142
The Cisco Aironet AIR-AP1142N-E-K9 is a versatile, legacy dual-band access point that uses 802.11n (Wi-Fi […]
The post Configuring the Cisco Aironet AP 1142 first appeared on Brezular's Blog.
Lab: Dual-Stack IS-IS Routing
Contrary to the OSPF world, where we have to use two completely different routing protocols to route IPv4 and IPv6 (unless you believe in the IPv4 address family in OSPFv3), IS-IS provided multi-protocol support from the very early days of its embracement by IETF. Adding IPv6 support was only a matter of a few extra TLVs, but even there, IETF gave us two incompatible ways of making IPv6 work with IS-IS.
Want to know more? You’ll find the details in the Dual-Stack (IPv4+IPv6) IS-IS Routing lab exercise.
IPv6 Support for Multiple Routers and Multiple Interfaces
Fernando Gont published an Individual Internet Draft (meaning it hasn’t been adopted by any IETF WG yet) describing the Problem Statement about IPv6 Support for Multiple Routers and Multiple Interfaces. It’s so nice to see someone finally acknowledging the full scope of the problem and describing it succinctly. However, I cannot help but point out that:
- I was ranting about that problem in 2009 (15 years ago) and did a summary of older rants in 2015.
- It was evident to everyone but the religious zealots that the only solution we have at the moment is either NAT (because stuff simply does not work otherwise) or host-based solutions that never got implemented (apart from a few rare cases of multipath TCP).
Anyway, Fernando wraps up his draft with: