Leaf-and-Spine Fabric Myths (Part 1)

Apart from the “they have no clue what they’re talking about” observation, Evil CCIE left a long list of leaf-and-spine fabric myths he encountered in the wild in a comment on one of my blog posts. He started with:

Clos fabric (aka Leaf And Spine fabric) is a non-blocking fabric

That was obviously true in the days when Mr. Clos designed the voice switching solution that still bears his name. In the original Clos network every voice call would get a dedicated path across the fabric, and the number of voice calls supported by the fabric equaled the number of alternate end-to-end paths.

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Woz takes a broad but hopeful view on AI, IoT

In a wide-ranging, free-form chat on Tuesday night in San Francisco at the 2018 Fog World Congress, legendary computing figure Steve Wozniak discussed the future of technology and its role in making the world a better place.Taking the stage alongside the senior director of Cisco’s corporate strategic innovation group, Helder Antunes, Wozniak took the audience through his personal history with technology, from phone hacking in the late 1970s, through his up-and-down relationship with Steve Jobs and Apple, to his current role as a sort of ambassador for the good that technology can do for the world.To read this article in full, please click here

Kernel of Truth episode 8: Network agility

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On this week’s Kernel of Truth episode, we’re breaking down network agility and why it’s important to you. The networking world loves a good acronym, but have no fear, this episode will also begin to unscramble the alphabet soup that comes with the technology. For this episode we brought in Attilla de Groot and Scott Edwards to discuss why agile networks are changing the tech world, how we got here, and what’s next.

If you’re interested in learning about the virtualization of IT, new innovations, and how that’s helping computing power become greater and faster than ever, this episode is for you. We discuss how Cumulus is making design methods and network architecture that’s easier for our customers to use and how we’re working to design a simpler, more freeing approach to networking and much more. So grab your headphones and sit back for 25 minutes of networking goodness!

 

Guest Bios

Attilla de Groot: Cumulus Networks; Attilla has spent the last 15 years at the cutting edge of Continue reading

Announcing Firewall Rules

Announcing Firewall Rules
Announcing Firewall Rules

Threat landscapes change every second. As attackers evolve, becoming more dynamic and devious, vulnerabilities materialize faster than engineers can patch their applications. Part of Cloudflare’s mission is to keep you and your applications safe. Today, Cloudflare is launching a new feature, giving customers what they have been requesting - fine-grained control over their incoming requests.

Cloudflare already offers a number of powerful firewall tools such as IP rules, CIDR rules, ASN rules, country rules, HTTP user-agent blocking, Zone Lockdown (for these URIs only allow traffic from those IPs), and our comprehensive managed rules within our WAF (Web Application Firewall). But sometimes, you need to combine the power of these to fully mitigate an attack, and to express a block rule that breaks the boundaries of the existing tools, to be able to “block traffic to this URI when the request comes from that IP and the user-agent matches one of these”.

Flexibility and Control

Announcing Firewall Rules

© Stefano Kocka : Source Wikipedia

Common themes arose when we spoke to customers about their needs and also reviewed feature requests that our customer support team had seen, and we categorised the top pieces of feedback and feature requests into three core needs:

  1. More flexibility Continue reading

Spray-on antennas will revolutionize the Internet of Things

In what could be a giant leap for Internet of Things (IoT) form factors, scientists say they have invented a spray-on antenna. And the bug-spray-like application will outperform traditional metal antennas, they claim.If it indeed does outperform traditional antennas, the clear, ink-like radiators will transform physical mediums used in constructing networks. Flexible substrates, windows, or data center walls even could be made into antennas, which would then drastically alter the data-collecting landscape.“Installing an antenna [could be] as easy as applying some bug spray,” an article on Drexel University’s website says.To read this article in full, please click here

Spray-on antennas will revolutionize the Internet of Things

In what could be a giant leap for Internet of Things (IoT) form factors, scientists say they have invented a spray-on antenna. And the bug-spray-like application will outperform traditional metal antennas, they claim.If it indeed does outperform traditional antennas, the clear, ink-like radiators will transform physical mediums used in constructing networks. Flexible substrates, windows, or data center walls even could be made into antennas, which would then drastically alter the data-collecting landscape.“Installing an antenna [could be] as easy as applying some bug spray,” an article on Drexel University’s website says.To read this article in full, please click here

Ryu measurement based control

ONOS measurement based control describes how real-time streaming telemetry can be used to automatically trigger SDN controller actions. The article uses DDoS mitigation as an example.

This article recreates the demonstration using the Ryu SDN framework and emulating a network using Mininet. Install both pieces of software on a Linux server or virtual machine in order to follow this example.

Start Ryu with the simple_switch_13 and ryu.app.ofctl_rest applications loaded:
ryu-manager $RYU_APP/simple_switch_13.py,$RYU_APP/ofctl_rest.py
Note: The simple_switch_13.py and ofctl_rest.py scripts are part of a standard Ryu installation. The $RYU_APP variable has been set to point to the Ryu app directory.
This demonstration uses the sFlow-RT real-time analytics engine to process standard sFlow streaming telemetry from the network switches.

Download sFlow-RT:
wget https://inmon.com/products/sFlow-RT/sflow-rt.tar.gz
tar -xvzf sflow-rt.tar.gz
Install the Mininet Dashboard application: 
sflow-rt/get-app.sh sflow-rt mininet-dashboard
The following script, ryu.js, implements the DDoS mitigation function described in the previous article: 
var ryu = '127.0.0.1';
var controls = {};

setFlow('udp_reflection',
 {keys:'ipdestination,udpsourceport',value:'frames'});
setThreshold('udp_reflection_attack',
 {metric:'udp_reflection',value:100,byFlow:true,timeout:2});

setEventHandler(function(evt) {
 // don't consider inter-switch links
 var link = topologyInterfaceToLink(evt.agent,evt.dataSource);
 if(link) return;

 // get port information
 var port = topologyInterfaceToPort(evt.agent,evt.dataSource);
 if(! Continue reading

What to Expect: CCIE Routing and Switching Written Exam Bootcamp

Our bootcamps are a great study resource for CCIE candidates. No matter whether you’re just starting out on your CCIE training journey, or have been studying for months, an INE bootcamp can help you gauge where you’re at in the study process and what you need to focus on before attempting your CCIE Exams.

What is a Bootcamp?

Bootcamps are intensive, live classes that typically last from 5-7 days. Bootcamps allow you to dive further into your study path in a small classroom environment with an in-person, expert INE instructor leading the way. Each bootcamp class will cover a specific list of topics tailored to the Cisco track and certification level you are studying. Our instructors will customize the training to focus on certain topics and technologies that best meet the individual requests of the students in your bootcamp.

What’s a Bootcamp Class Actually Like?

In our Written Routing and Switching Bootcamp you will learn about Switching, RIP & EIGRP, OSPF, BGP, MPLS, Redistribution and Evolving Technologies. Our 7 time CCIE, expert-instructor, Rohit Pardasani, will not only help you understand all of the essential R&S topics for this exam, he will also share study techniques and prepare you for Continue reading

Episode 36 – State Of IPv6

In this community roundtable episode George Michaelson, Ed Horley, and Leslie Daigle join Network Collective to talk about the current state of IPv6 deployment.

 

George Michaelson
Guest
Ed Horley
Guest
Leslie Daigle
Guest

Jordan Martin
Host
Russ White
Host

Outro Music:
Danger Storm Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 3.0 License
http://creativecommons.org/licenses/by/3.0/

The post Episode 36 – State Of IPv6 appeared first on Network Collective.

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