Archive

Category Archives for "Networking"

Removing OVS Configuration Settings

I’ve written quite a bit about Open vSwitch (OVS), but I realized recently that despite all the articles I’ve written I still haven’t talked about how to remove a configuration setting to OVS. I’m fixing that now with this article.

As part of my ongoing mission to give back to the open source community, I recently started making contributions and improvements to the OVS web site; specifically, I’ve been reformatting the configuration cookbooks to make them more readable (and to clean up the HTML source). Along the way, I’ve been adding small bits of content here and there. Most recently, I just updated the QoS rate-limiting entry, and I wanted to add information on how to remove the QoS settings.

Normally, you can remove an OVS configuration setting using the ovs-vsctl remove command. For example, if you set a VLAN tag on an port with this command:

ovs-vsctl set port vnet0 tag=100

Then you could remove that VLAN tag with this command:

ovs-vsctl remove port vnet0 tag 100

Note the slight syntactical difference in the two commands; the remove command expects four parameters.

It turns out, however, that this command won’t work for all configuration parameters. In some Continue reading

CCIE Collaboration Success :: Student Spotlight

We’d like to thank Jon Woloshyn for his testimonial! Jon recently passed the CCIE Collaboration lab! Here’s what Jon had to say:

“I attended iPexpert’s CCIE Collaboration 10-Day Bootcamp in August 2014 and I’m happy to say that on November 11th I passed the CCIE Collaboration exam on my first attempt.

I owe a lot of my success to Andy Vassar and iPexpert. The volume 1 workbook coupled with week 1 of the 10—Day CCIE Collaboration Lab Bootcamp helped solidify my understanding and comfort level with all of the technologies on the blueprint. Having my own un-shared, dedicated pod with the exact lab hardware that’s on the lab during that week to practice on day and night was huge. Being able to ask Andy every question that came to mind and get a detailed response was awesome. The fact the he would break from the lesson and lab up the questions being asked to prove the technology made the class very flexible and almost tailored to each student who required additional knowledge.

Week 2 of the 10-day course was the 1-Week Lab Experience (OWLE). I would not have passed without this week. Andy shared his lab strategy and at first Continue reading

iPexpert’s Newest “CCIE Wall of Fame” Additions 11/21/2014

Please Join us in congratulating the following iPexpert clients who have passed their CCIE lab!

  • Andre Mitchell, CCIE #44619 (Collaboration)
  • Gaurav Vasudeva , CCIE #42760 (Routing and Switching)

We Want to Hear From You!

Have you passed your CCIE lab exam and used any of iPexpert’s or Proctor Labs self-study products, or attended a CCIE Bootcamp? If so, we’d like to add you to our CCIE Wall of Fame!

Friday News Analysis: Open Networking Foundation, Dave Ward on Open

Open Networking Foundation Extends Conformance Testing to Non-Members “The Open Networking Foundation (ONF), a non-profit organization dedicated to accelerating the adoption of open Software-Defined Networking (SDN), today announced it has extended the ONF OpenFlow™ Conformance Testing Program to include testing for non-ONF members. Companies interested in receiving an OpenFlow Certificate of Conformance for […]

Not Raising Red Flags While Looking For A New Job

A reader wrote to me, explaining that they were unhappy in their current job situation, and queried how they might be able look for a new job without raising any red flags with their existing employer. Tricky, but I have a few thoughts, having done this a time or two over my career. […]

In the Data Center, No One Can Hear You Lose Your Hearing

Working for a data center-focused reseller/integrator like H.A. Storage Systems, I spend my fair share of time in various data center environments. I have, for years, elected to use some sort of hearing protection when in these facilities. I have constantly been amazed, though, at how few other workers in data centers do the same.

Honestly, I’m not sure why most people I see in data center facilities don’t use hearing protection. Perhaps they think they’ll only be on the data center floor for a few minutes. We all know it never goes like that! Perhaps they think it makes it too hard to hear co-workers. Personally, I find it easier to communicate with someone when I have ear protection on. Maybe workers think it’s not loud enough for ear protection to be necessary. Unfortunately, this isn’t true in most cases.

Can You Hear Me Now?

As an example, I was recently down at the Sungard Availability Services colo facility in Philadelphia. It’s one of the largest colos in the immediate area with 230,000 square feet of raised floor. I was in there all day long with one of my customers, for two days while we traced out Continue reading

Doxxing defense: Remove your personal info from data brokers

Many women gamers and developers, as well as those who support them, have lately come under attack from online trolls. A common intimidation tactic that trolls use is "doxxing," or publicly exposing their targets' personal details, including home address, phone number and even financial records.To read this article in full or to leave a comment, please click here

Maturity and Evolution of SDN

A few weeks ago I read this article from Craig Matsumoto on SDN Central.

At first I read it with a bit of a smile, but for some reason it has actually started to bother me a little. In this article, Craig summarizes a talk by Scott Shenker about SDN and a proposal for an SDNv2 that would fix the things that are wrong with SDNv1. In a way this represents what is wrong with our industry. We create a new version or create a new name for a concept that is not particularly well defined to begin with, and in many interpretations is far broader than is assumed in the pre-fixed version.

Many folks still believe that OpenFlow defines SDN. And that all the limitations of a basic protocol invalidate or limit the capabilities of an evolving concept like SDN. Why do we feel such a need to increment a version of an undefined term to make it sound like we are creating something new and different?

In SDNv2, we would still have separation of control and date (at least all that work is not wasted), but there are three major differences between it and the “old” SDN concepts. Continue reading

The Resolvers We Use

The Internet's Domain Name System is a modern day miracle. It may not represent the largest database that has ever been built, but nevertheless it's truly massive. The DNS is consulted every time we head to a web page, every time we send an email message, or in fact every time we initiate almost any transaction on the Internet. We assume a lot about the DNS. For example, content distribution networks are observed to make use of the location of the DNS resolver as being also the same location as the user. How robust is this assumption of co-locality of users and their resolvers? Are users always located "close" to their resolvers? More generally, what is the relationship between the end user, and the DNS resolvers that they use? Are they in fact closely related? Or is there widespread use of distant resolvers?

Who’s Watching?

It's been more than a year since Edward Snowden released material concerning the activities of US agencies in the area of cyber-intelligence gathering. A year later, and with allegations of various forms of cyber spying flying about, it's probably useful to ask some more questions. What is a reasonable expectation about privacy and the Internet? Should we now consider various forms of digital stalking to be "normal"? To what extent can we see information relating to individuals' activities online being passed to others?

The changing of the guard: Telecom Style-Part 1

The sale of a incumbent local exchange carrier (ILEC) aka the local telephone company can be much more complicated than one might think, ordinary folks anyway. Networking & IT  professionals most likely have a different viewpoint as migrations are a fundamental part of the IT field. Such a transaction becomes more complicated when triple play […]

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Mitchell Lewis

Mitchell is a young technology professional with an interest in networking & communications. He takes an interest in the ever changing telecom space as well as other networking technologies (datacenter etc). His main hobby project is overseeing the expansion of broadband into a co-operative campground, shares of which are owned by a family member.

Mitchell currently is a Cisco Certified Entry Level Tech (CCENT Certified) with intentions of obtaining higher as time permits.He graduated from the Connecticut Technical High School system with a focus in Information Systems Technology (Combination of Higher Ed MIS & Computer Science). While there he developed the production computing platform for his academic department( servers, networking, desktop).

He is currently pursing higher education from the UCONN School of Business & welcomes any opportunity to further advance his experience in the IT Field & professional knowledge.

The Linux ip Command – An Ostensive Overview

It came to my attention and I was rather surprised to learn a while back that the Linux ifconfig command has been deprecated for quite some time by the Linux ip command set. The ip command isn’t new to me and I’ve recognised its advantages for some time but considering its ‘elevated’ status I thought […]

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Steven Iveson

Steven Iveson

Steven Iveson, the last of four children of the seventies, was born in London and has never been too far from a shooting, bombing or riot. He's now grateful to live in a small town in East Yorkshire in the north east of England with his wife Sam and their four children.

He's worked in the IT industry for over 15 years in a variety of roles, predominantly in data centre environments. Working with switches and routers pretty much from the start he now also has a thirst for application delivery, SDN, virtualisation and related products and technologies. He's published a number of F5 Networks related books and is a regular contributor at DevCentral.

The post The Linux ip Command – An Ostensive Overview appeared first on Packet Pushers Podcast and was written by Steven Iveson.

Stop Doing Post Mortems & Root Cause Analysis With indeni

Indeni has technology that can predict known types of network failures using pre-mortem analysis.

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Sponsored Blog Posts

The Packet Pushers work with our vendors to present a limited number of sponsored blog posts to our community. This is one. If you're a vendor and think you have some blog content you'd like to sponsor, contact us via [email protected].

The post Stop Doing Post Mortems & Root Cause Analysis With indeni appeared first on Packet Pushers Podcast and was written by Sponsored Blog Posts.

Wipebook – A Portable Whiteboard

It is a stereotype, but engineers really do like whiteboards. Problem is, you can’t carry one around with you. Plus there’s still a few unenlightened employers who don’t provide whiteboards. Enter the Wipebook, a spiral-bound notebook made of whiteboard-like pages:

I normally carry a notebook for scratching out notes while talking to customers, sketching diagrams, working through problems, etc. I don’t archive these notes – most are just short-term things, and I shred them. Important stuff gets turned into OmniFocus tasks/emails/etc.

So the Wipebook looks perfect for me. My wife bought one for me recently, and I’ve started using it at work. So far, it’s working as expected. I can quickly scribble notes, sketch a diagram, make corrections, etc. When I’m done with it, I wipe the page down.

It’s not perfect – the pages don’t always wipe down perfectly, and obviously it gets bumped around in my bag. So it won’t last forever. But it’s a nice touch that I can open & close the bindings, so I can easily get rid of any pages that are too beaten up.

The pens have a small eraser on the end, but it’s only suitable for very minor corrections. I have a Continue reading

The Proof Is in The Facebook Data Center Pudding

In case you missed it, Wired just exposed the elephant in the room with last week’s article on the next generation Facebook data center.

For years, anyone who’s had to build out or run a network has handed over large sums of money to the networking hardware titans, without the freedom to choose what to run on that hardware. But I’m sure if you’re someone who placed one of those orders, the thought crossed your mind if this was always going to be the norm.

Every time before you clicked or signed on that dotted line, you wondered whether it’s worth buying from the incumbents and playing in their locked-in world. Maybe deep down you had some burning desire to break away, but were afraid to stray from the blue chip way of life.

I feel your pain and it’s okay because we all want to maximize the value of our dollar. That’s why we all shop for the best choice and at the best price point; otherwise, we will just wait and buy another day.

I mean, you have the freedom to buy the servers you want, so why not have the freedom to buy the network gear that Continue reading