Bash #1. Automating Troubleshooting (Cumulus) Linux Networking
Hello my friend,
Very often at our zero-to-hero network automation training we are asked, what is the benefit of Bash? Why do we need to know Bash, if everyone is talking about Bash? The question is absolutely legitimate. One of the interesting and also legitimate answers I’ve just figured the last week.
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Do you finally write about network automation?
Everything in your network and IT operational processes can be automated. It is just matter of the resources (time, money, efforts) you spent on that against the gain you are obtaining. Basically, that is something what financial guys and girls call ROI (Return On Investments). The bigger the outcome and the lower the effort, the better the overall automation solution.
In our automation trainings we explain various use cases and success (and failure) strategies, how to build the (network) automation systems and tools, to make sure your gain is maximum. Our instructors have an extensive experience building Continue reading
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
Network Analysis 1. Setting up and Getting Started with Batfish in Multivendor Network with Cisco, Arista, and Cumulus.
Hello my friend,
The new year we start with a new topic, which is a configuration analysis of the multivendor networks. We have a passion both to create our own open source tools and to use existing, creating by other teams and project. Today we will start dive in one of such a tool.
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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 Continue reading
5 years on air.
Hello my friend,
Have we thought 5 years ago that we would manage to keep the blog running for such a long period of time and would create such a huge amount of useful information for the community? Definitely not. And that’s why it is even important we managed to achieve such a milestone. Thank a lot each of you for your support, ideas, feedbacks, shared on social medias and likes! That means a lot for us. Please, continue doing so 
The last 12 month were absolutely incredible. The COVID-19 pandemic struck word so much that noone could ever believe. As a result, we, pretty much as a whole work, worked from home all past 12 moths… Which was an unusual experience. However, we used this time (in fact, due to no necessity to spend time on commute, we have more time to work) productively working on various projects for you, our dear readers. So, what have we managed to achieve?
Network Automation and Programmability Fundamentals with Cisco Press
One of the massive achievements was to complete the book Network Automation and Programmability Fundamentals, which was published by Cisco Press in May 2021. The journey for us started back in Continue reading
Tools 8. Visual Analysis of the Network Path with Open Source Databases and Python
Hello my friend,
Over the past several articles we have taken a look into the most popular tools for the network troubleshooting. To be precise, we have covered an approach to find your public IP address in a programmable way, how to measure your Internet connectivity speed with Speedtest, how to measure the connectivity speed between your endpoints using iPerf, rapid check of hosts presence in the network with fping, how to check the quality of the path through the network with MTR, and how to see what are in the packets you have in your network. Covering these tools for you and sharing ideas about automation with them led us to creating a new open source tool, which we are happy to share with the community. This time we decided not to think long on its name and just called it the Traceroute Analyzer.
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What is the network automation?
Tools 7. Show me your packets … with TCP dump
Hello my friend,
When something goes wrong with the distributed application, where the network is involved (e.g., between client and web service, or between frontend and backend of services), the network is a first thing to be blamed. After the troubleshooting, it is often turned out that the network is innocent, but we need first need to prove it.
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Automated troubleshooting for automated networks?
The truth is that automation helped me so many times to figure out the root cause of the network outages or malfunctions that I even stopped counting that. I may say that automaton solutions work perfect, if you create them to solve your issues and tailor to your environment.
That’s what our Live Network Automation Training (10 weeks) and Automation with Nornir (2 weeks) are all about: to show you real automation in a real environment with multiple vendors together. No matter what those vendors are, the automation principles, tools Continue reading
SP. Part 9. Health check of Segment Routing Traffic Engineering (SR-TE) tunnels with seamless BFD in Nokia SR OS
Hello my friend,
For a long time we haven’t posted blogs about pure network technologies. However, recently we were working on some interesting use case, which so far is not yet covered at a level of the working details nowhere in the internet. As such, we decided to share with you our findings and working details.
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How automation can help with SR-TE in SP network?
In some (big) networks the BGP-SR-TE is a good signal the SR-TE policies, so that the PE routers can build the SR-TE tunnels without the need to configure them locally. However, the BGP-SR-TE requires a full pledged SDN controller, so that you can generate the SR-TE policy in the backend using some UI/API and send the policies down to the network elements using the BGP. If you want to have a somewhat simpler setup, you may need need to deploy the tunnels manually. In this case, the automation is your closest Continue reading
Visualise and Analyse Your Data Centre Fabric with HAWK
Hello my friend,
Some time ago in LinkedIn we announced that we are working on the tool, which will allows you to model and analyse your network. As one of our primary focuses is data centres, we started from there. Despite it is an early stages, but we are happy and proud to introduce you HAWK: Highly-efficient Automated Weapon Kit. For now, this is a collection of the tools for the network management and analysis, but probably later we will put it under a joint hoot of some front-end, who knows…
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Where is the the border between network automation and software development?
In order to automate any network operation, you need to write a script, even if that is a simple one. On the other hand, any script is a program or software. This means that the creating of the scripts for the network automation is a form of the software development. And it is fun. Continue reading
Tools 6. Where are my packets lost? MTR edition.
Hello my friend,
after show pause we continue our blog series about the most popular network troubleshooting tools, which humankind has ever created. Today we’ll take a look at one of the most useful tool to obtain the information about the path between two endpoints and possible packet drops over that path. Ladies and gentlemen, please, welcome MTR.
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Can automation help with figuring what happened where?
In case of the infrastructure problems (networks, servers, VMs, containers), the time matters a lot. The quicker we can find the issue and fix that, the better it will be for our applications and our customers. Automation without doubts one of the key components, which allows you to quickly find and fix your issues.
In our trainings, the Live Network Automation Training (10 weeks) and Automation with Nornir (2 weeks), we explore a lot of real use cases, where the automation helps you to validate the state of you Continue reading
pygnmi 9. The safest way to store credentials for network devices.
Hello my friend,
Recently we were asked, what is the safest way to store the credentials for network devices to your automation tools (e.g., the one based on Python and gNMI). Building the network automation solutions for a while, we have a good answer to you.
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What is the most promising network automation protocol ?
gNMI was created by Google to manage their data centres and backbone network and is widely used by other biggest companies worldwide. However, it doesn’t mean that only the big guys can benefit from that. Every company and network can get the advantage of a single protocol for the configuration, operation, and streaming telemetry in their network provided your network devices support that.
At our trainings, advanced network automation and automation with Nornir (2nd step after advanced network automation), we give you detailed knowledge of all the technologies relevant:
- Data encoding (free-text, XML, JSON, YAML, Protobuf)
- Model-driven network automation Continue reading
pygnmi 8. Securing the gNMI connectivity with self-signed certificates.
Hello my friend,
Continuing our explanation of the pyGNMI, we’ll take a loon into the security aspect of the tool. Namely, we will take a look how quickly and easily you can implement the encryption between your host running pyGNMI and the gNMI speaking network function.
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Where is the GNMI in the Network Automation?
The automation world (network and not only) can at a high level be split into text-based automation and model-driven automation. The text based automation is all about Linux systems, where we typically template the whole configuration files, put them in the corresponding folders and then restart daemons. The model driven approach is where we communicate with the network devices using the NETCONF, RESTCONF or gNMI based on the YANG modules. At the current moment, gNMI is most dynamically developing protocol. We not only teaches you how it works and when to use it, but we also created a Python library, Continue reading
SEC 4. Complete guide for integrating Nokia, Arista, Cumulus, as well as CentOS and Raspberry PI Linux in your own PKI
Hello my friend,
In one of the previous blogposts we have share the details how you can build the containerised PKI relying Docker, Alpine Linux and OpenSSL. Today we’ll show how you can use it.
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How automation can increase the security?
In one of the recent articles dedicated to threats to the national security with respect to 5G caused by the current operation models in the big service providers, one the network automation were named as one of the key mitigation approaches. The reason is very simple: network automation allows you to keep (or even increase) the pace of the network changes with increasing the stability without increasing the size of your network operation teams.
We absolutely agree with this statement. We have observed ourselves that in many cases the key technical competence for service providers is being outsourced and in certain cases the service providers have to rely on the external parties to perform Continue reading
Tools 5. Searching for live hosts with fping. IPv4 and IPv6 version.
Hello my friend,
Quite often, when we do the troubleshooting of our networks and systems, we want to figure out, which hosts are alive in the certain range. The quickest and the easiest way (though, not 100% accurate) is to run the ping against a specific range of IPs. There is a brilliant tool for this purpose, which is called fping.
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Can automation help to find issues in the network quickly?
All the time, when the outage is happening in the production environment, either with the network or server/application infrastructure, the race starts to restore the service as soon as possible. Automation is a key helper there.
In our trainings, the Live Network Automation Training (10 weeks) and Automation with Nornir (2 weeks), we explore a lot of real use cases, where the automation helps you to validate the state of you network and change it if necessary. You will learn the whole spectre of Continue reading
SEC 3. Building your own containerised PKI (root CA) with Linux and Docker to simplify and secure network automation
Hello my friend,
You know our passion to network automation. We truly believe, that this is the only sustainable way for the network development and operation. In the same time, one the key goals of the automation is to make your network secure and safe. Therefore, the security of the automation and communication channels used by automation is very important. So today we’ll take a look how to build
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Can automation make your network better?
Automation is the key component of the perpetual engine of your network development and operation. It allows you to run the network quick, stable, and safe. And we are willing you to benefit as much as you can from that.
We have created a new training, which is focused only on the Nornir and you can use it for the network (and not only) automation. It is an organic extension of our network automation training, which assumes you are already Continue reading
Tools 4. Checking bandwidth between your servers, VMs, containers or even PIs and Android/Apple phone using iperf
Hello my friend,
We hope you are doing well and staying safe during this COVID times. To make your stay a bit more pleasant, we are offering you and interesting read, which will give you ideas how to test network performance between your endpoints, which can be any Server, virtual machine (VM), container, or even Raspberry PI node. Yes, we continue our troubleshooting series. Take a brew, and get started.
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Can automation help with fixing your network issues?
Automation is your extra pair of hands. Or even more than that. Capability to create the network automation solutions, from a basic scripts for info collection or simple configuration to complicated logic, which takes into account exiting environment and is integrated with your other OSS/BSS, is one of the key skills, what allows you to build a successful career in the constantly changing network field.
We have created a new training, which is focused only on the Nornir Continue reading
pygnmi 7. Integration of pygnmi with Nornir
Hello my friend,
With this blogpost we continue the series of pygnmi tutorials covering various use cases of our Python library created to help you with managing your network devices via GNMI. And today we show you, how easily you can use it with Nornir, if you like this automation framework.
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Can it be enough automation?
Yes, it can be. But how to understand, what you should automate and what shouldn’t? What are the success strategies to start the automation projects and what are the receipts of disaster? What is the most efficient ways and technologies depending on context, and how to identify? Should you still stick to CLI? Is the model-driven automation all the time suitable? There are gazillions of questions about the network automation, which you may have in your mind, but don’t know whom to ask. We are here to help you.
At our trainings, advanced network automation and automation with Nornir (2nd Continue reading
Tools 3. Checking your connectivity bandwidth with Speedtest
Hello my friend,
Continuing our discussion about the network troubleshooting tools we can’t pass by one of the most popular and widely used, which is named SpeedTest.
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Can automation help with performance troubleshooting?
Doing the collection and initial analysis of the information during the troubleshooting could be quite a time-consuming task. On the other hand, the troubleshooting of the live outages should be as quick as possible to minimise the downtime of the affected services. That’s where the automation can help you.
In our network automation training we explain how to use existing open-source tools and create your own with Ansible, Bash and Python. Leveraging them and all possible interfaces (CLI, NETCONF, RESTCONF, gNMI) we teach you how to effectively build, operate and troubleshoot your network.
Brief description
From the name of the tool, SpeedTest, it is obvious that the main goal is to measure the “speed”. In fact, it measures Continue reading
DC. Part 17. High-available server cluster connected to DC fabric.
Hello my friend,
In the vast majority of cases we speak about the network, network devices and network configuration. Which is absolutely legitimate, as we write about the networks. However, sometimes exactly the same network technologies live in the server world and do the same things under different names. So today we’ll take a look how to create the high-available server cluster using the Keepalived.
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Servers are perfect for automation
The network exists to span the applications and customers. However, it doesn’t host applications itself; instead, they are hosted on the servers. That’s why automation of the servers is very big topic and, in all honesty, the automation originally has started in the server world.
In the same time, the tools and approaches you learn at our network automation training are universal: they are applicable both for the network and servers automation. Automate all things!
At our network automation training we explore the Linux setup and Continue reading
Merry Christmas and Happy New Year 2021
Dear friend,
This year was unbelievable. But despite all the horrible things related to COVID19 and lockdown, you and we are still alive. Moreover, the networking and automation industry is growing. It means, we are together on the right side, but we need continuously sharp existing and develop new skills.
We sincerely thank you for your interest in our projects, blogs and trainings. For your questions, comments and suggestions. It means for us a lot.
We wish you Merry Christmas and Happy New Year! Stay healthy and safe during the holiday times and the whole new year.
All the best,
Team Karneliuk.com
pygnmi 3. Usage of gNMI Capabilities.
Hello my friend,
Some time ago we’ve started sharing with you the details of pygnmi – our new open-source Python library created to simplify the management of the network elements with gNMI. The library is already almost fully operational and we want to start sharing the usage scenarios with you.
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Don’t you want to automate boring stuff?
Every job, especially network operation, has lots of routing tasks, which are boing and time consuming. Some of such tasks could be already automated in your company, but the vast majority is still waiting you. In our trainings:
- We explain the advantages and challenges of network automation in multivendor networks (leveraging network operating systems from Cisco, Nokia, Arista, Cumulus).
- We teach you how to reach quick wins in network automation to fuel your automation projects for a long run.
- We covers all the details of the automation protocols, data models and teach you how to apply it in real Continue reading