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Category Archives for "Networking"

Validate Ansible YAML Data with JSON Schema

When I published the Optimize Network Data Models series a long while ago, someone made an interesting comment along the lines of “You should use JSON Schema to validate the data model.”

It took me ages to gather the willpower to tame that particular beast, but I finally got there. In the next installment of the Data Models saga I described how you can use JSON Schema to validate Ansible inventory data and your own YAML- or JSON-based data structures.

To learn more about data validation, error handling, unit- and system testing, and CI/CD pipelines in network automation, join our automation course.

Keep reading

Validate Ansible YAML Data with JSON Schema

When I published the Optimize Network Data Models series a long while ago, someone made an interesting comment along the lines of “You should use JSON Schema to validate the data model.”

It took me ages to gather the willpower to tame that particular beast, but I finally got there. In the next installment of the Data Models saga I described how you can use JSON Schema to validate Ansible inventory data and your own YAML- or JSON-based data structures.

To learn more about data validation, error handling, unit- and system testing, and CI/CD pipelines in network automation, join our automation course.

Keep reading

Docker DDoS testbed


Docker testbed describes how to use Docker Desktop to build a test network to experiment with real-time sFlow streaming telemetry and analytics. This article extends the testbed to experiment with distributed denial of service (DDoS) detection and mitigation techniques described in Real-time DDoS mitigation using BGP RTBH and FlowSpec.

Start a Host sFlow agent using the pre-built sflow/host-sflow image:
docker run --rm -d -e "COLLECTOR=host.docker.internal" -e "SAMPLING=10" \
--net=host -v /var/run/docker.sock:/var/run/docker.sock:ro \
--name=host-sflow sflow/host-sflow
Start ExaBGP using the pre-built sflow/exabgp image. ExaBGP connects to the sFlow-RT analytics software and displays BGP RTBH / Flowspec controls sent by sFlow-RT:
docker run --rm sflow/exabgp
In a second terminal window, start an instance of the sFlow-RT analytics software using the pre-built sflow/ddos-protect image:
GW=`docker network inspect bridge -f '{{range .IPAM.Config}}{{.Gateway}}{{end}}'`

SUBNET=`docker network inspect bridge -f '{{range .IPAM.Config}}{{.Subnet}}{{end}}'`

docker run --rm -p 6343:6343/udp -p 8008:8008 -p 1179:1179 --name=sflow-rt \
sflow/ddos-protect -Dddos_protect.router=$GW -Dddos_protect.as=65001 \
-Dddos_protect.enable.flowspec=yes -Dddos_protect.group.local=$SUBNET \
-Dddos_protect.mode=automatic \
-Dddos_protect.udp_amplification.action=filter \
-Dddos_protect.udp_amplification.threshold=5000
Open the sFlow-RT dashboard at http://localhost:8008/
The sFlow Agents gauge confirms that sFlow is being received from the Host sFlow agent. Now access the Continue reading

How the Gap embraced the edge

One of the best-known clothing retailers in the world has embraced edge computing technology and realized significant operational advantages as a consequence, one of its senior technical staff said in a presentation at the recent Edge Computing World conference.The Gap operates more than 2,500 stores in North America and handles about $10 billion in transactions per year. The company has switched from traditional point-of-sale technology to a system based almost entirely on Apple’s iOS products, as iPads replace cash registers and scanner guns across sales floors.To read this article in full, please click here

Gartner: IT spending to grow 4% in 2021

Worldwide IT spending is forecast to reach $3.8 trillion in 2021, an increase of 4% from 2020, according to research firm Gartner, but still shy of pre-pandemic levels. IT spending in 2020 is expected to total $3.6 trillion, down 5.4% from 2019.Certain industries facing prolonged lockdowns due to COVID-19, such as entertainment and air transport, have cut IT spending by more than 30% in 2020, according to Gartner, which delivered the current outlook for the global IT market at its virtual IT Symposium/Xpo 2020 Americas.   Learn more:To read this article in full, please click here

Gartner: IT spending to grow 4% in 2021

Worldwide IT spending is forecast to reach $3.8 trillion in 2021, an increase of 4% from 2020, according to research firm Gartner, but still shy of pre-pandemic levels. IT spending in 2020 is expected to total $3.6 trillion, down 5.4% from 2019.Certain industries facing prolonged lockdowns due to COVID-19, such as entertainment and air transport, have cut IT spending by more than 30% in 2020, according to Gartner, which delivered the current outlook for the global IT market at its virtual IT Symposium/Xpo 2020 Americas.   Learn more:To read this article in full, please click here

Technologies that Didn’t: Network Operating Systems

For those with a long memory—no, even longer than that—there were once things called Network Operating Systems (NOS’s). These were not the kinds of NOS’s we have today, like Cisco IOS Software, or Arista EOS, or even SONiC. Rather, these were designed for servers. The most common example was Novell’s Netware. These operating systems were the “bread and butter” of the networking world for many years. I was a Certified Netware Expert (CNE) version 4.0, and then 4.11, before I moved into the routing and switching world. I also deployed Banyan’s Vines, IBM’s OS/2, and a much simpler system called LANtastic, among others.

What were these pieces of software? They were largely built around providing a complete environment for the network user. These systems began with file sharing and directory services and included a small driver that would need to be installed on each host accessing the file share. This small driver was actually a network stack for a proprietary set of protocols. For Vines, this was VIP; for Netware, it was IPX. Over time, these systems began to include email, and then, as a natural outgrowth of file sharing and email, directory services. For some time, there Continue reading

Full Stack Journey 047: Using Kubernetes And Crossplane To Provision Cloud Infrastructure

Today's Full Stack Journey episode explores the Crossplane project, which uses APIs in Kubernetes and public cloud providers to allow you to provision and manage cloud services and infrastructure from Kubernetes. Crossplane maintainer Daniel Mangum is our guide.

The post Full Stack Journey 047: Using Kubernetes And Crossplane To Provision Cloud Infrastructure appeared first on Packet Pushers.

Disowning a process in Linux

When you want a process to continue running even after you log off a Linux system, you have a couple options.One of them is to use the disown command. It tells your shell to refrain from sending a HUP (hangup) signal to the process when you log off. So, the process continues running. This can be very handy whenever you start a process and then, for some reason, you can’t stay logged in and wait until it finishes.[Get regularly scheduled insights by signing up for Network World newsletters.] The disown command is a shell built-in. This means that you don’t have to install it to use it, but it also means that it won’t be available if you use a shell that doesn’t support it. For those of us using bash and related shells (zsh, ksh etc.), disown should be available and you can verify this with a command like this that lists shell built-ins and then looks for "disown":To read this article in full, please click here

Cisco targets WAN edge with new router family

Cisco has launched a family of core and branch routers that take aim at refining secure, cloud resource access distributed at the edge.Cisco Catalyst 8000 edge router family includes three models--the high-end 8500 for data-center or colocation customers, the 8300 for branch users, and the software-based 8000 for virtual environments and feature support for advanced routing, SD-WAN,  security and secure-access service edge (SASE)--depending on customer requirements.To read this article in full, please click here

Bot Attack trends for Jan-Jul 2020

Bot Attack trends for Jan-Jul 2020
Bot Attack trends for Jan-Jul 2020

Now that we’re a long way through 2020, let’s take a look at automated traffic, which makes up almost 40% of total Internet traffic.

This blog post is a high-level overview of bot traffic on Cloudflare’s network. Cloudflare offers a comprehensive Bot Management tool for Enterprise customers, along with an effective free tool called Bot Fight Mode. Because of the tremendous amount of traffic that flows through our network each day, Cloudflare is in a unique position to analyze global bot trends.

In this post, we will cover the basics of bot traffic and distinguish between automated requests and other human requests (What Is A Bot?). Then, we’ll move on to a global overview of bot traffic around the world (A RoboBird’s Eye View, A Bot Day and Bots All Over The World), and dive into North American traffic (A Look into North American Traffic).  Lastly, we’ll finish with an overview of how the coronavirus pandemic affected global traffic, and we’ll take a deeper look at European traffic (Bots During COVID-19 In Europe).

On average, Cloudflare processes 18 million HTTP requests every second. This is a great opportunity to understand how bots shape the Continue reading

Going Postal

The Internet was not the first communications system constructed as compound service, where the end-to-end service was built using the services provided by many individual service providers. International telephony was constructed in a similar manner, and predating the telephone was the international postal service. In this article I’d like to look at the Universal Postal Union's track record of trying to construct a fair and efficient way to allow each service provider to be compensated for their part in the construction of the delivered end-to-end service. As with the Internet, it all comes down to the choice of the framework for settlement and peering between providers.
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