Internets of Interest for 28th March 2014
Collection of useful, relevant or just fun places on the Internets for 28th March 2014 and a bit commentary about what I’ve found interesting about them: Brocade – Brocade Extends Ethernet Fabric Leadership – Brocade hasn’t given up on the Campus. This announcement from February talks about their switch platform, most interesting is that […]
The post Internets of Interest for 28th March 2014 appeared first on EtherealMind.
Cisco Internal VLAN Usage
About a month ago I worked on an old CatOS switch. Working on this switch reminded me about some of the differences between CatOS and IOS. One of the big differences is how a Layer 3 routed interface is configured between the two OS versions. On a Catalyst running IOS, it is almost identical as […]
Author information
The post Cisco Internal VLAN Usage appeared first on Packet Pushers Podcast and was written by Charles Galler.
Does Network Lifecycle Management Make Sense?
Recently, we met with a friend who has done an amazing job of understanding the lifecycle management of virtual machines (VMs). As the CTO of a very large cloud provider, he explained in deep detail how he took advantage of Moore’s Law and doubled the amount of VMs in each rack each year, while maintaining or shrinking the cost per rack. As a result, he has doubled the amount of earning potential in each data center while driving cost down, even as his staff is ripping out servers long before their traditional three- to four-year lifecycle and purchasing new ones. He is buying servers at a 3-to-1 ratio over a three-year period when compared with a typical server lifecycle, yet his cost to operate the data center is going down and his productivity is going up by 2x every year. Amazing!
While we enjoyed learning of his success, when we hear these stories, we think “Could this have the same type of impact somewhere in the network?” It got us to ask why customers traditionally hang on to their top-of-rack switches for four or five years and sometimes longer.
What is different about the network versus servers?
Obviously, Continue reading
SAN Automation with Python and Jinja
One of my least favorite things to do in my day job is create or maintain a zoning configuration on a fibre channel switch, such as a Cisco Nexus or MDS. It’s tedious, very error prone, and annoying when changes need to be made. I wrote earlier in the week on the value of using a templating language like Jinja to define the structure of a switch configuration, but dynamic enough to accept all kinds of input from some higher-level intelligence elsewhere.SAN Automation with Python and Jinja
One of my least favorite things to do in my day job is create or maintain a zoning configuration on a fibre channel switch, such as a Cisco Nexus or MDS. It’s tedious, very error prone, and annoying when changes need to be made. I wrote earlier in the week on the value of using a templating language like Jinja to define the structure of a switch configuration, but dynamic enough to accept all kinds of input from some higher-level intelligence elsewhere.How to become a network engineer
Original content from Roger's CCIE Blog Tracking the journey towards getting the ultimate Cisco Certification. The Routing & Switching Lab Exam
If you have arrived on this page then I would assume you know what a network engineer is and would like to find out how to become a network engineer? If you are not sure what a network engineer is or does then the picture below explains it very well Picture courtesy of http://perceptionvsfact.com/ A […]
Post taken from CCIE Blog
Original post How to become a network engineer
Troubleshooting with Wireshark [Riverbed lab kit]
A while ago I attended a Wireshark webinar from Riverbed in which they presented the tool, some beginner and intermediate users troubleshooting scenarios and some lab kit. Now I got an e-mail that they made it available for download at http://www.riverbed.com/wireshark-virtual-tour Part of this Lab Kit were available in the Virtual World Tour 2014 webinar […]Three reasons why Networking is a pain in the IaaS, and how to fix it
In this post I share the slides, audio recording, and short outline of a presentation I gave at the Melbourne VMUG conference (Feb 2014) called “Three reasons why Networking is a pain in the IaaS, and how to fix it”. As network technologists we know that when the compute architecture changes, the network architecture changes […]Three reasons why Networking is a pain in the IaaS, and how to fix it
In this post I share the slides, audio recording, and short outline of a presentation I gave at the Melbourne VMUG conference (Feb 2014) called “Three reasons why Networking is a pain in the IaaS, and how to fix it”.
As network technologists we know that when the compute architecture changes, the network architecture changes with it. Consider the precedent. The transition from mainframe to rack servers brought about Ethernet and top-of-rack switches. Blade servers introduced the blade switch and a cable-less network. And of course the virtual server necessitating the software virtual switch and a hardware-less network. At each iteration, we observe the architecture change occurring at the edge, directly adjacent to compute.
We can look at this superficially and say, “yes, the network architecture changed”. However if you think about it, the catalyzing change in each shift was the operational model, with intent to increase agility and reduce costs. The architecture change was consequential. Without compute, there is no reason for a network. Networking, both as a profession and technology, exists as a necessary service layer for computing. Without a network, computing is practically useless. As such, the capabilities of the network will either enable or impede Continue reading
Three reasons why Networking is a pain in the IaaS, and how to fix it
In this post I share the slides, audio recording, and short outline of a presentation I gave at the Melbourne VMUG conference (Feb 2014) called “Three reasons why Networking is a pain in the IaaS, and how to fix it”.
As network technologists we know that when the compute architecture changes, the network architecture changes with it. Consider the precedent. The transition from mainframe to rack servers brought about Ethernet and top-of-rack switches. Blade servers introduced the blade switch and a cable-less network. And of course the virtual server necessitating the software virtual switch and a hardware-less network. At each iteration, we observe the architecture change occurring at the edge, directly adjacent to compute.
We can look at this superficially and say, “yes, the network architecture changed”. However if you think about it, the catalyzing change in each shift was the operational model, with intent to increase agility and reduce costs. The architecture change was consequential. Without compute, there is no reason for a network. Networking, both as a profession and technology, exists as a necessary service layer for computing. Without a network, computing is practically useless. As such, the capabilities of the network will either enable or impede Continue reading
Three reasons why Networking is a pain in the IaaS, and how to fix it
In this post I share the slides, audio recording, and short outline of a presentation I gave at the Melbourne VMUG conference (Feb 2014) called “Three reasons why Networking is a pain in the IaaS, and how to fix it”.
As network technologists we know that when the compute architecture changes, the network architecture changes with it. Consider the precedent. The transition from mainframe to rack servers brought about Ethernet and top-of-rack switches. Blade servers introduced the blade switch and a cable-less network. And of course the virtual server necessitating the software virtual switch and a hardware-less network. At each iteration, we observe the architecture change occurring at the edge, directly adjacent to compute.
We can look at this superficially and say, “yes, the network architecture changed”. However if you think about it, the catalyzing change in each shift was the operational model, with intent to increase agility and reduce costs. The architecture change was consequential. Without compute, there is no reason for a network. Networking, both as a profession and technology, exists as a necessary service layer for computing. Without a network, computing is practically useless. As such, the capabilities of the network will either enable or impede Continue reading
Learn Python
Around six years ago, I decided to start a website called packetlife.net. Maybe you've heard of it. Most people turn to a purpose-built content management system like Wordpress or Drupal for such an endeavor, but I needed greater flexibility to achieve some of the projects I had in mind. This meant I needed to learn a programming language and write a good amount of the site's logic myself.
I already had some experience dabbling in PHP, but wasn't thrilled with it. I figured if I was going to learn a new language, it should be useful as a general purpose language and not just for building a web site. After a bit of research and deliberation, I chose Python (and the Django web framework).
The purpose of this post is to convince networkers with little to no experience writing code to learn Python. In the past I've encouraged fellow networkers to pick up any programming language, as it's more important to think like a programmer than it is to gain proficiency in a particular language. However, I've realized that many people get stuck on which language they want to learn, lose motivation, and end up not growing proficient Continue reading
OpenDaylight at Networking Field Day 7
Networking Field Day 7 was the third Tech Field Day event I attended as a delegate, and as expected, it was a blast. Its always good to be reunited with old friends, especially in this kind of environment, where constant technical discussions are…….well, they’re just going to happen. There were certainly some common undertones in every single presentation. One big example is OpenDaylight - nearly every vendor had at least something to say about it.OpenDaylight at Networking Field Day 7
Networking Field Day 7 was the third Tech Field Day event I attended as a delegate, and as expected, it was a blast. Its always good to be reunited with old friends, especially in this kind of environment, where constant technical discussions are…….well, they’re just going to happen. There were certainly some common undertones in every single presentation. One big example is OpenDaylight - nearly every vendor had at least something to say about it.Pre-bestpath Cost Community – What is it?
This post represents the solution and explanation for quiz-21. It is a very long post describing Pre-bestpath community, Point of Insertion, offset list and other networking hacks employed to tackle a less common problem. Make yourself a coffee and start reading...
Integrated hybrid OpenFlow control of HP switches
The previous article provided an example of large flow marking using an Alcatel-Lucent OmniSwitch 6900 switch. This article discusses how to replicate the example using HP Networking switches.
At present, the following HP switch models are listed as having OpenFlow support:
- FlexFabric 12900 Switch Series
- 12500 Switch Series
- FlexFabric 11900 Switch Series
- 8200 zl Switch Series
- HP FlexFabric 5930 Switch Series
- 5920 Switch Series
- 5900 Switch Series
- 5400 zl Switch Series
- 3800 Switch Series
- HP 3500 and 3500 yl Switch Series
- 2920 Switch Series
HP's OpenFlow implementation supports integrated hybrid mode - provided the OpenFlow controller pushes a default low priority OpenFlow rule that matches all packets and applies the NORMAL action (i.e. instructs the switch to apply default switching / routing forwarding to the packets).
In Continue reading
Network Configuration Templates Using Jinja2
We’ve all been there at some point in our careers - especially those that work for VARs. You’re presented with a bunch of new gear that needs to be configured and deployed, and you’re tasked with making the magic happen. It was great to wake up yesterday to read Jason Edelman’s post on Ansible for networking - taking an approach to network automation that’s built upon existing, proven tools just makes sense, especially for the use case of initial configuration, but hopefully beyond.Network Configuration Templates Using Jinja2
We’ve all been there at some point in our careers - especially those that work for VARs. You’re presented with a bunch of new gear that needs to be configured and deployed, and you’re tasked with making the magic happen. It was great to wake up yesterday to read Jason Edelman’s post on Ansible for networking - taking an approach to network automation that’s built upon existing, proven tools just makes sense, especially for the use case of initial configuration, but hopefully beyond.Dell Aims for the Clouds with Z9500 Spine
While at Networking Field Day 7, we got a small preview of a new switch Dell Networking has just announced, the Z9500. At some point I’ll have another post coming discussing more of Dell’s presentation at NFD7, but I wanted to briefly talk about this new product and what it brings to the table for Dell.
To be frank, Dell’s acquisition of Force10 Networks originally felt to me like a “me too” play so that Dell could compete with Cisco UCS and HP in the “full data center stack” play combining compute, storage, and networking in a single SKU or a playbook of blessed configurations. I wasn’t really expecting Dell to innovate all that much in this space. But based on the information I have at this point, I think that position is unfounded.
Here’s a picture of the new beast from a demo rack Dell showed us at NFD:
Dell Z9500
To summarize the hardware: it’s a hell of a lot of density. The Z9500 platform presents 132 line-rate 40G ports in a 3RU chassis. So, if one were inclined, one could potentially cram 14 such chassis into a standard 42RU cabinet to concentrate 1,848 40G ports into Continue reading
Ordered FIB
In a past post, we’ve discussed microloops in link state protocols. If we examine a small ring topology (if you come to my Interop talk, you’ll discover that ring topologies are the heart of network convergence), we can see where and how a microloop forms. If the link between A and B fails, A and […]
