EVPN-VXLAN Explainer 6 – Symmetrical IRB

EVPN-VXLAN Explainer 6 - Symmetrical IRB

Now let's continue our look at routing with EVPN-VXLAN as we focus on symmetrical IRB.

This post is essentially building upon a lot of what we covered in the previous post. So, if you haven't read that yet, please do, then meet me back here. This post will make a lot more sense if you do.

🔬 Symmetrical IRB in Detail

While symmetrical and asymmetrical IRB have the same functional outcome; to route inter-subnet traffic, there are a number of major differences in the requirements and configuration of each.
Most notably, symmetrical IRB frees us from the requirement to configure all VLANs & L2VNIs on all VTEPs.

Here's an overview of the features and components that we'll be covering:

Symmetrical IRB Architecture Notes

  • Symmetrical IRB offers a more scalable approach to routing VXLAN traffic because VTEPs are not required to have knowledge of all destination clients, they do not need to hold an ARP cache entry for a destination, unlike asymmetrical IRB.
  • VTEPs are only configured with the VLANs, subnets and VNIs that host locally connected clients.
  • To ensure successful end-to-end connectivity for inter-subnet traffic, a number of new requirements and features are deployed with symmetrical IRB:

Getting Tough with Cyberinsurance

I’ve been hearing a lot of claims recently about how companies are starting to rely more and more on cyberinsurance policies to cover them in the event of a breach or other form of disaster. While I’m a fan of insurance policies in general I think the companies trying to rely on these payouts to avoid doing any real security work is going to be a big surprise to them in the future.

Due Diligence

The first issue that I see is that companies are so worried about getting breached that they think taking out big insurance policies are the key to avoiding any big liability. Think about an organization that holds personally identifiable information (PII) and how likely it is that they would get sued in the event of a breach. The idea is that cyberinsurance would pay out for the breach and be used as a way to pay off the damages in a lawsuit.

The issue I have with this is that companies are expecting to get paid. They see cyberinsurance as a guaranteed payout instead of a last resort. In the initial days of taking out these big policies the insurers were happy to pay out Continue reading

NIST’s pleasant post-quantum surprise

NIST’s pleasant post-quantum surprise
NIST’s pleasant post-quantum surprise

On Tuesday, the US National Institute of Standards and Technology (NIST) announced which post-quantum cryptography they will standardize. We were already drafting this post with an educated guess on the choice NIST would make. We almost got it right, except for a single choice we didn’t expect—and which changes everything.

At Cloudflare, post-quantum cryptography is a topic close to our heart, as the future of a secure and private Internet is on the line. We have been working towards this day for many years, by implementing post-quantum cryptography, contributing to standards, and testing post-quantum cryptography in practice, and we are excited to share our perspective.

In this long blog post, we explain how we got here, what NIST chose to standardize, what it will mean for the Internet, and what you need to know to get started with your own post-quantum preparations.

How we got here

Shor’s algorithm

Our story starts in 1994, when mathematician Peter Shor discovered a marvelous algorithm that efficiently factors numbers and computes discrete logarithms. With it, you can break nearly all public-key cryptography deployed today, including RSA and elliptic curve cryptography. Luckily, Shor’s algorithm doesn’t run on just any computer: it needs Continue reading

Cloudflare’s view of the Rogers Communications outage in Canada

Cloudflare’s view of the Rogers Communications outage in Canada
Cloudflare’s view of the Rogers Communications outage in Canada

(Check for the latest updates at the end of this blog: Internet traffic started to come back at around July 9, 01:00 UTC, after 17 hours)

An outage at one of the largest ISPs in Canada, Rogers Communications, started earlier today, July 8, 2022, and is ongoing (eight hours and counting), and is impacting businesses and consumers. At the time of writing, we are seeing a very small amount of traffic from Rogers, but we are only seeing residual traffic, and nothing close to a full recovery to normal traffic levels.

Based on what we’re seeing and similar incidents in the past, we believe this is likely to be an internal error, not a cyber attack.

Cloudflare Radar shows a near complete loss of traffic from Rogers ASN, AS812, that started around 08:45 UTC (all times in this blog are UTC).

Cloudflare’s view of the Rogers Communications outage in Canada

What happened?

Cloudflare data shows that there was a clear spike in BGP (Border Gateway Protocol) updates after 08:15, reaching its peak at 08:45.

Cloudflare’s view of the Rogers Communications outage in Canada

BGP is a mechanism to exchange routing information between networks on the Internet. The big routers that make the Internet work have huge, constantly updated lists of the possible routes that can be Continue reading

Weekend Reads 070822

We kick off this edition of the weekend reads with a few articles on security. Misconfigured cloud storage buckets and a failure to implement good password practices are, as always, a major source of security issues.


We found that only 15 websites were following best practices. The remaining 105 either leave users at risk for password compromise or frustrated from being unable to use a sufficiently strong password (or both).


A misconfigured Amazon S3 bucket resulted in 3TB of airport data (more than 1.5 million files) being publicly accessible, open, and without an authentication requirement for access, highlighting the dangers of unsecured cloud infrastructure within the travel sector.


An unlucky fat-fingering precipitated the current crisis: The client had accidentally deleted the private key needed to sign new firmware updates.

Another study showing the importance of DNS abuse in spreading malware.


In April, I participated in the panel session ‘Real Life Perspectives on Regional DNS Abuse in APAC’ at the APAC DNS Forum 2022, during which I and my fellow panellists shared examples of DNS incidents that we’ve seen in the Asia Pacific region and how we, as a community, can improve how we mitigate these threats.

Another reminder that Continue reading

Network Programmability and Automation, Second Edition

In late 2015, I was lucky enough to be part of a small crew of authors who launched a new book project targeting “next-generation network engineering skills.” That book, Network Programmability and Automation, was published by O’Reilly and has garnered praise and accolades for tackling head-on the topics that network engineers should consider mastering as the field of network engineering continues to grow and evolve. I was excited about that announcement, and I’m even more excited to announce that the early release of the second edition of Network Programmability and Automation is now available!

2nd edition book cover

The original team of authors—Jason Edelman, Matt Oswalt, and myself—are joined this time around by Christian Adell. Christian works with Jason at Network to Code, and it has been a tremendous pleasure to get to know Christian (a little bit, at least!) as part of this project so far. I am impressed with his knowledge and experience, and I think it really adds to the book. Jason and Matt, of course, need no introductions; they are both industry leaders and are well-known in the network automation space.

Check out Jason and Christian’s announcement blog post here.

I am, once again, humbled and honored Continue reading

Automatic Signed Exchanges may dramatically boost your site visitor numbers

Automatic Signed Exchanges may dramatically boost your site visitor numbers
Automatic Signed Exchanges may dramatically boost your site visitor numbers

It’s been about nine months since Cloudflare announced support for Signed Exchanges (SXG), a web platform specification to deterministically verify the cached version of a website and enable third parties such as search engines and news aggregators to serve it much faster than the origin ever could.

Giving Internet users fast load times, even on slow connections in remote parts of the globe, is to help build a better Internet (our mission!) and we couldn’t be more excited about the potential of SXG.
Signed Exchanges drive quite impressive benefits in terms of performance improvements. Google’s experiments have shown an average 300ms to 400ms reduction in Largest Contentful Paint (LCP) from SXG-enabled prefetches.  And speeding up your website usually results in a significant bounce rate reduction and improved SEO.

faster websites= better SEO and lower bounce rates

And if setting up and maintaining SXGs through the open source toolkit is a complex yet very valuable endeavor, with Cloudflare’s Automatic Signed Exchanges it becomes a no-brainer. Just enable it with one click and see for yourself.

Automatic Signed Exchanges may dramatically boost your site visitor numbers

Our own measurements

Now that Signed Exchanges have been available on Chromium for Android for several months we dove into the change in performance Continue reading

What is eBPF? How is it used?

This will be a Series of Posts on eBPF extensively covering XDP and its usage.

https://ebpf.io

New technology, implemented in Linux, extends kernel functionalities without having to modify the kernel, Safe to execute with a verification engine, JIT compiler and LLVM (Virtual Environment) basically a safe and secure tiny VM.

Medium – https://raaki-88.medium.com/what-is-ebpf-how-is-it-used-f897e8fb0934

Some Background

As my career is mainly in Network Engineering, when some talks about Network performance my initial thoughts jump to increase network throughput, Port-Density, High speed and secure interconnect, I recently came across Systems Performance by Brendan Gregg. I have to say I have never ever imagined that the role is sought out, I went through the book (https://www.amazon.co.uk/Systems-Performance-Enterprise-Brendan-Gregg/dp/0133390098) and I was indeed mind blown by the granularity that one can look into an individual system.

I definitely would recommend anyone in Networking/Cloud/Systems Engineering to go through this book if you haven’t t already, it exposes a whole new level of Linux Kernel and E-BPF and Performance methodologies (Chapter 2) which I instantly fell in love with.

What Inspired me?

When I first saw the book I was under the initial impression that this was meant for Linux system Continue reading

Using the eval command in Linux to run variables as commands

There are probably a lot of Linux users who have never encountered the eval command. In fact, it’s not really a "command", but a bash built-in that’s meant to process the value of a variable as a command. For example, if you set up a variable that includes the command to display the current time in Sydney, Australia, it would probably look like this:$ dt="TZ='Australia/Sydney' date"You could then run it like this:$ eval $dtThu Jul  7 06:32:14 AM AEST 2022Doing that can save you the trouble of memorizing the date command syntax and specifying a time zone, but let’s look a little more closely at eval to see what else it can do for you.To read this article in full, please click here

Using the eval command in Linux to run variables as commands

There are probably a lot of Linux users who have never encountered the eval command. In fact, it’s not really a "command", but a bash built-in that’s meant to process the value of a variable as a command. For example, if you set up a variable that includes the command to display the current time in Sydney, Australia, it would probably look like this:$ dt="TZ='Australia/Sydney' date"You could then run it like this:$ eval $dtThu Jul  7 06:32:14 AM AEST 2022Doing that can save you the trouble of memorizing the date command syntax and specifying a time zone, but let’s look a little more closely at eval to see what else it can do for you.To read this article in full, please click here

What is Wi-Fi 7, and will it replace wired Ethernet?

New Wi-Fi standards appear in such rapid succession that it’s often difficult to evaluate the differences between Wi-Fi 5, Wi-Fi 6, and Wi-Fi 6E—all of which are standards adopted in commercial products. And now there’s Wi-Fi 7.Chinese networking-equipment vendor H3C has released what it says is a Wi-Fi 7 router even though the Wi-Fi 7 standard isn’t expected to be finalized until 2024.What is Wi-Fi 7? Wi-Fi 7 or 802.11be is the next Wi-Fi standard being worked on by the Institute of Electrical and Electronics Engineers that promises speeds of a whopping 46Gbps, nearly five times faster than Wi-Fi 6, as well as reduced latency. Wi-Fi 7 (also known as Extremely High Throughput) is expected to deliver higher spectrum efficiency, higher power efficiency, better interference mitigation, higher capacity density, and higher cost efficiency. To read this article in full, please click here

What is Liposomal Curcumin (and How Can It Help You Live a Better Life?)

Liposomal curcumin is a powerful anti-inflammatory that has been shown to be effective in a wide range of inflammatory diseases. It is also a potent antioxidant and has been shown to protect cells from damage caused by oxidative stress.

Liposomal curcumin is thought to be more effective than regular curcumin because it is better absorbed by the body. One study showed that liposomal curcumin was absorbed into the bloodstream four times better than regular curcumin.

Liposomal curcumin has been shown to be effective in treating inflammatory diseases such as arthritis, Crohn’s disease, and ulcerative colitis. It is also thought to be helpful in managing symptoms of Alzheimer’s disease and other forms of dementia.

How does it work?

Liposomal curcumin works by inhibiting the production of inflammatory molecules called cytokines. It is also a powerful antioxidant and protects cells from damage caused by oxidative stress.

Benefits of Liposomal Curcumin

There are many potential benefits of liposomal curcumin. Some of the most well-studied benefits include:

Reduced inflammation

Liposomal curcumin has been shown to reduce inflammation in a wide range of inflammatory diseases, including arthritis, Crohn’s disease, and ulcerative colitis. It is thought to work by inhibiting the production of inflammatory molecules called Continue reading

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