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 […]
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Putting the Application in SDN
Putting the Application in SDN
by Steve Harriman, VP of Marketing - March 25, 2014
We would like to highlight a couple of recent articles about SDN that reflect Packet Design’s perspective on the technology. Arthur Cole wrote in Enterprise Networking Planet about “SDN in the Enterprise: It’s the Applications, Stupid.” He rightly asserts that the value of SDN isn’t in the architecture itself, but in the applications that the environment supports. It is understandable that during the genesis of a technology, the majority of effort is spent in making it work, but we should not lose site of the fact that optimal application performance is the key to deploying SDN more broadly. And we as an industry are not nearly ready to effectively manage applications across software-defined networks.
In fact, Cole cites an article written by our own CTO Cengiz Alaettinoglu in Data Center Knowledge about how traditional, manual management methods are inadequate in a programmable, automated network environment. We need to automate network management best practices and processes to give human operators the visibility and control needed to adequately manage SDN applications in the data center and across the WAN. Continue reading
Performance optimizing hybrid OpenFlow controller
This article discusses the evolving architecture of software defined networking (SDN) and the role of analytics and traffic engineering. InMon's sFlow-RT controller is used to provide practical examples of the architecture.
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| Figure 1: Fabric: A Retrospective on Evolving SDN |
First generation SDN controllers were designed before the edge / core split became Continue reading
Restoring Trust in the Internet – Part 2
In my last post I talked about the broken trust in the Internet. Now let’s talk about steps we need to take to restore that trust. First, we need to realize that trust is regained by proving we are trustworthy. There is nothing we can do, or say, that will instantly restore trust; it is […]
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The post Restoring Trust in the Internet – Part 2 appeared first on Packet Pushers Podcast and was written by Jonathan Strine.
Taking the Old Approach to Cisco Live 2014
I was just reading through Bob’s blog post from today and wanted to give a rebuttal of sorts. In his post, Bob tells us that’s he’s going to be at Cisco Live US in San Francisco this year but he won’t be coming on the Full Conference pass like he usually does. He’s going with the Social Event pass this year, which is actually a great, great way to attend. I know several people who are thinking about scaling back to the Social Event pass as well, and there’s nothing wrong with doing it like that. There are some things that it doesn’t get you, though.
The Social Event pass means no breakout sessions. These are the bread-and-butter of the conference and the real technical reason that I try to go each year (listen to me talk like I’m a 20-year NetVet…LOL). Yes, most of the sessions are available on Cisco Live 365 afterwards, but that leaves two problems for me. First of all, I will never actually make the time to go back and sit through these sessions after the event. It’s just something that won’t happen with life and work and everything going on. Secondly, I cannot sit Continue reading
The Foundation of Network Programmability
Ever since I entered this field, I’ve been interested in this concept of “network programmability”. Forgetting for a second what we’ve been talking about in the past few years since the advent of the “SDN tsunami”, even the ability to automate simple infrastructure tasks at a small scale has grabbed my attention. It’s important to note something here; the CLI is a wonderful tool. So many vendors take the wrong approach and say the CLI is going away in lieu of pretty GUIs and APIs, as if someone can’t write a really good CLI to consume a really good API.The Foundation of Network Programmability
Ever since I entered this field, I’ve been interested in this concept of “network programmability”. Forgetting for a second what we’ve been talking about in the past few years since the advent of the “SDN tsunami”, even the ability to automate simple infrastructure tasks at a small scale has grabbed my attention. It’s important to note something here; the CLI is a wonderful tool. So many vendors take the wrong approach and say the CLI is going away in lieu of pretty GUIs and APIs, as if someone can’t write a really good CLI to consume a really good API.Ansible for Networking
[This article is the outcome of some great conversations and exchanges I’ve had recently with Jeremy Schulman (@nwkautomaniac) around automation and Devops in the world of networking. Thank you to Jeremy for those late tweaks before getting this posted! Thanks to Kirk Byers (@kirkbyers) as well - he was also gracious enough to respond to clarify a few things and assisted with this post indirectly.]
There have been numerous articles written that describe the what and the why of Devops. Reading through a few of these, you find references to CAMS --- you’ll read how “Devops is about CAMS.” CAMS stands for Culture, Automation, Measurement, and Sharing. Imagine working in an environment where automation is embraced? We know most networks are not leveraging nearly any type of automation. While we usually talk about engineers (of all types) not embracing automation, is the harsh reality most organizations are from having the right culture to embrace automation?
There have been numerous articles written that describe the what and the why of Devops. Reading through a few of these, you find references to CAMS --- you’ll read how “Devops is about CAMS.” CAMS stands for Culture, Automation, Measurement, and Sharing. Imagine working in an environment where automation is embraced? We know most networks are not leveraging nearly any type of automation. While we usually talk about engineers (of all types) not embracing automation, is the harsh reality most organizations are from having the right culture to embrace automation?
What if there was a way to start testing network automation without taking a risk in a production environment? And to top it off, the network automation was being done using some of the same tools that Continue reading
Taking a New Approach to Cisco Live 2014
It’s getting to be that time of year again when geeks across North America (and beyond) start getting excited for Cisco Live! The buzz is starting a bit early this year, but that’s because Cisco Live is about a month earlier this year (May 18-22) than it has been in recent years.
Introduction
Many of the exciting details of the event have surfaced at this point, including the announcement of Salman Khan, founder of Khan Academy as the closing guest keynote speaker, and that the Customer Appreciation Event will feature Lenny Kravitz and the Imagine Dragons as musical acts. We’ve even seen this year’s backpack design, courtesy of a couple Tweets from Cisco’s Kathleeen Mudge:
@Rob_Coote @blakekrone @scottm32768 @networkingnerd @BobMcCouch @fryguy_pa This is the backpack, no Dora this time pic.twitter.com/ZJ504qJ66P
— Kathleen Mudge (@KathleenMudge) March 20, 2014
@Rob_Coote @blakekrone @scottm32768 @networkingnerd @BobMcCouch @fryguy_pa My pics aren’t doing it justice. It’s cool pic.twitter.com/J2ZI8OgQzl
— Kathleen Mudge (@KathleenMudge) March 20, 2014
Last year, I put together a post of Cisco Live tips, most of which are just as applicable this year as last. My personal approach, however, will be a bit different this year.
Plans Continue reading
Show 184 – The Future of Networking Part 2 as Inspired by #NFD7
At Networking Field Day 7, the delegates were treated to vendor demonstrations that challenged our thinking about the future of networking. Perhaps the industry is not agreed on just how we’ll implement and operate our networks in the coming years, but one thing is for certain. The landscape will be different. In this and the previously […]
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The post Show 184 – The Future of Networking Part 2 as Inspired by #NFD7 appeared first on Packet Pushers Podcast and was written by Ethan Banks.
Review: Hadoop Operations
Hadoop Operations Eric Sammer Hadoop is one of those applications all data centers seem to need to support – and there is a lot of information out there about how Hadoop works, how to use it, and how to build Hadoop systems. From these, it’s pretty easy to glean a general set of requirements for […]
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HP Comware-based Switches – Link Aggregation
The 3Com/HPN/H3C based Switches offers the utilization of interfaces such as Ethernet, Fast Ethernet, GigabitEthernet or TenGigabitEthernet. The Link Aggregation feature allows the gathering of many ports in order to increase the link’s velocity concerning the full duplex communication between the two devices.
In Link-Aggregation mode the ports are utilized in parallel, supporting the bandwith’s growth and expansion, without the need of buying an additional hardware.
For example, we can use four 100Mb ports in each device to form a communication between two switches using 400Mb among them. However, the utilization of redundant enlaces raises the possibility of loops within the network. Link Aggregation avoids the situation which the blocking state or loops, stop the gathered ports, treating them as one single interface. For the STP, SNMP and VLANs the interfaces are treated as one logical link.
Other name used for the Link Aggregation is EtherChannel.
The LACP protocol is part of the 802.3ad specification for Link Aggregation, allowing that switches and servers negotiate the port groups with different manufactures automatically. Both ports should offer constant support to the protocol, so that the Link Aggregation could work correctly.
Some Switch models can utilise the PagP (Cisco) protocol or interface Continue reading