Peering into binary files on Linux

Any file on a Linux system that isn't a text file is considered a binary file--from system commands and libraries to image files and compiled programs. But these files being binary doesn't mean that you can't look into them. In fact, there are quite a few commands that you can use to extract data from binary files or display their content. In this post, we'll explore quite a few of them.file One of the easiest commands to pull information from a binary file is the file command that identifies files by type. It does this in several ways--by evaluating the content, looking for a "magic number" (file type identifier), and checking the language. While we humans generally judge a file by its file extension, the file command largely ignores that. Notice how it responds to the command shown below.To read this article in full, please click here

Peering into binary files on Linux

Any file on a Linux system that isn't a text file is considered a binary file--from system commands and libraries to image files and compiled programs. But these files being binary doesn't mean that you can't look into them. In fact, there are quite a few commands that you can use to extract data from binary files or display their content. In this post, we'll explore quite a few of them.file One of the easiest commands to pull information from a binary file is the file command that identifies files by type. It does this in several ways--by evaluating the content, looking for a "magic number" (file type identifier), and checking the language. While we humans generally judge a file by its file extension, the file command largely ignores that. Notice how it responds to the command shown below.To read this article in full, please click here

Fugaku still reigns as the world’s fastest supercomputer

Fugaku, the supercomputer built by Fujitsu, remains at number one in the TOP500 list of the fastest supercomputers in the world, where it is still three times faster than the nearest competition.The contest for the fastest remains tight, with only one new entry into the top 10 on the latest list—Perlmutter, at the National Energy Research Scientific Computing (NERSC) Center at Lawrence Berkeley National Laboratory, which is part of the US Department of Energy. It joins the list at number five and bumps down numbers six through 10 from the previous list published in November 2020.(A system called Dammam-7 dropped off the top 10.)To read this article in full, please click here

Fugaku still reigns as the world’s fastest supercomputer

Fugaku, the supercomputer built by Fujitsu, remains at number one in the TOP500 list of the fastest supercomputers in the world, where it is still three times faster than the nearest competition.The contest for the fastest remains tight, with only one new entry into the top 10 on the latest list—Perlmutter, at the National Energy Research Scientific Computing (NERSC) Center at Lawrence Berkeley National Laboratory, which is part of the US Department of Energy. It joins the list at number five and bumps down numbers six through 10 from the previous list published in November 2020.(A system called Dammam-7 dropped off the top 10.)To read this article in full, please click here

Using WireGuard on macOS via the CLI

I’ve written a few different posts on WireGuard, the “simple yet fast and modern VPN” (as described by the WireGuard web site) that aims to supplant tools like IPSec and OpenVPN. My first post on WireGuard showed how to configure WireGuard on Linux, both on the client side as well as on the server side. After that, I followed it up with posts on using the GUI WireGuard app to configure WireGuard on macOS and—most recently—making WireGuard from Homebrew work on an M1-based Mac. In this post, I’m going to take a look at using WireGuard on macOS again, but this time via the CLI.

Some of this information is also found in this WireGuard quick start. Here I’ll focus only on using macOS as a WireGuard client, not as a server; refer to the WireGuard docs (or to my earlier post) for information on setting up a WireGuard server. I’ll also assume that you’ve installed WireGuard via Homebrew.

Generating Keys

The first step is to generate the public/private keys you’ll need. If the /usr/local/etc/wireguard (or the /opt/homebrew/etc/wireguard for users on an M1-based Mac) directory doesn’t exist, you’ll need to first create that directory. (It didn’t exist Continue reading

How VMware IT Achieved Zero Trust in the Data Center: a Step-by-Step Approach

Security keeps getting more complex, and despite a multitude of products, tools and processes, organizations find it challenging to prevent 100 percent of breaches or unwanted access. Zero Trust holds the promise of achieving tighter security by only trusting network traffic that is specifically permitted by a security policy. While the task appears daunting, those organizations that follow a step-by-step approach can achieve success.

The process followed by VMware IT (VMIT) can serve as a blueprint for other organizations, removing some of the mystery and complexity. VMIT embarked on a Zero Trust project for data center security to prevent unwanted lateral movement, restricting communication among workloads to only the minimum needed to complete their jobs. The goal was to make Zero Trust the new normal for all applications in the data center. To do so, the team needed to gain a complete understanding of all applications, down to the workload level. Once understood, effective policies can be crafted to permit only the desired behavior.

Step one: macro-segmentation

Achieving Zero Trust fits neatly into a five-step approach (see A Practical Path to Zero Trust in the Data Center white paper), which starts with macro-segmenting the network and culminates in micro-segmenting all Continue reading

Department of Defense works to integrate battlefield intel networks

If yours is like most enterprises, it is under intense competitive pressure to understand faster, decide faster, and act faster in an increasingly dynamic environment.For businesses, that environment is the economy. But for the U.S. Department of Defense (DoD), the environment in which they must leverage technology and tactics against deadly adversaries is more like a battlefield. And all but the most self-aggrandizing sales directors would agree that the stakes on the battlefield are considerably higher than growing revenue and capturing market share. (Not that they are trivial!) Read more: Cisco tool taps telemetry for network, security analyticsTo read this article in full, please click here

Department of Defense works to integrate battlefield intel networks

If yours is like most enterprises, it is under intense competitive pressure to understand faster, decide faster, and act faster in an increasingly dynamic environment.For businesses, that environment is the economy. But for the U.S. Department of Defense (DoD), the environment in which they must leverage technology and tactics against deadly adversaries is more like a battlefield. And all but the most self-aggrandizing sales directors would agree that the stakes on the battlefield are considerably higher than growing revenue and capturing market share. (Not that they are trivial!) Read more: Cisco tool taps telemetry for network, security analyticsTo read this article in full, please click here

The Department of Defense, networking, and the speed of relevance

If yours is like most enterprises, it is under intense competitive pressure to understand faster, decide faster, and act faster in an increasingly dynamic environment.For businesses, that environment is the economy. But for the U.S. Department of Defense (DoD), the environment in which they must leverage technology and tactics against deadly adversaries is more like a battlefield. And all but the most self-aggrandizing sales directors would agree that the stakes on the battlefield are considerably higher than growing revenue and capturing market share. (Not that they are trivial!) Read more: Cisco tool taps telemetry for network, security analyticsTo read this article in full, please click here

The Department of Defense, networking, and the speed of relevance

If yours is like most enterprises, it is under intense competitive pressure to understand faster, decide faster, and act faster in an increasingly dynamic environment.For businesses, that environment is the economy. But for the U.S. Department of Defense (DoD), the environment in which they must leverage technology and tactics against deadly adversaries is more like a battlefield. And all but the most self-aggrandizing sales directors would agree that the stakes on the battlefield are considerably higher than growing revenue and capturing market share. (Not that they are trivial!) Read more: Cisco tool taps telemetry for network, security analyticsTo read this article in full, please click here

Webinars in the First Half of 2021

It’s time for another this is what we did in the last six months blog post. Instead of writing another wall-of-text, I just updated the one I published in early January. Here are the highlights:

That’s about it for the first half of 2021. I’ll be back in early September.

Webinars in the First Half of 2021

It’s time for another this is what we did in the last six months blog post. Instead of writing another wall-of-text, I just updated the one I published in early January. Here are the highlights:

That’s about it for the first half of 2021. I’ll be back in early September.

Network Analysis 2. Analysing Network Configuration Consistency (Sanity check, BGP, Routes) with Batfish for Cisco, Arista, and Cumulus

Hello my friend,

In the previous blogpost we’ve introduced the Batfish and how to set it up. Today we’ll take a look how to perform the analysis of the configuration to figure out discrepancies, which may lead to broken operation of your network.



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Network Analysis as Part of Automation?

In software development we have a concept called CI/CD (Continuous Integration/Continuous Delivery). In a nutshell, it’s a methodology, which incorporates mandatory testing of configuration (code, software version, etc) before bringing it to production. The main idea behind it is that automated testing and validation will make sure that code is stable and fit for purpose. Automated testing? That’s where the automation comes to the stage.

And automation is something what we are experts in. And you can benefit from that expertise as well.

In our network automation training we follow zero to hero approach, where we start with the basics including Linux operation and administration topped with Continue reading

my CKA/CKAD study plan

This is the story of studying Kubernetes basics from the perspective of network engineer. I had basic Linux background, some free time, and willingness to discover this brave new world of containers, pods and microservices.

I think one of the best ways to do this kind of studying is to follow the blueprint of recognized industry certification. This gives you a concrete study plan and bring structure to your knowledge from the very beginning.

There are such certifications in Kubernetes world – CKA and CKAD from CNCF/The Lunix Foundation. It’s quite popular certifications (as k8s in general), and so there a LOT of study material out there in the Internet. Below is the list of sources I’ve used.

  1. KubeAcademy from VMware. Collection of short courses to study the 101 of containers, Docker and Kubernetes. I’ve found it useful to do first quick dive into this area of knowledge.
  2. Kubernetes: Up and Running. The must-read book about Kubernetes architecture and concepts. Explains everything in great details.
  3. Great cources from Mumshad Mannambeth on Udemy – CKA and CKAD. This courses contain almost everything you need to know to pass the exams, and also have a lot of practice labs to consolidate theoretical Continue reading
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