Fast Reroute Mechanisms

Network reliability is an important measure for deployability of sensitive applications. When a link, node or SRLG failure occurs in a routed network, there is inevitably a period of disruption to the delivery of traffic until the network reconverges on the new topology. Fast reaction is essential for the failed element. There are two approaches […]

Author information

Orhan Ergun

Orhan Ergun, CCIE, CCDE, is a network architect mostly focused on service providers, data centers, virtualization and security.

He has more than 10 years in IT, and has worked on many network design and deployment projects.

In addition, Orhan is a:

Blogger at Network Computing.
Blogger and podcaster at Packet Pushers.
Manager of Google CCDE Group.
On Twitter @OrhanErgunCCDE

The post Fast Reroute Mechanisms appeared first on Packet Pushers Podcast and was written by Orhan Ergun.

How portable is your network operating system?

Conversations are swirling throughout the tech industry about whether white box switches are disrupting the networking industry, similarly to how white box manufacturers helped commoditize the server industry. If this recent InfoWorld article, is not enough to persuade you, consider that even John Chambers himself has recently chimed in on the threat of white boxes eroding Cisco’s margins.                                                                                         

The idea of white box switching from a Pica8 perspective is to help create an operating abstraction between the “metal” (in our case white box switches from original device manufacturers, or ODMs) and the network operating system (OS) itself.  When that’s created, you have a degree of OS portability.

In a typical first meeting with a prospect, we frequently get asked if they can port a version of our OS on their existing Cisco switches. At first blush, it makes sense but let’s examine the three key issues that need to be addressed to truly Continue reading

Nexus 7k – Getting Started Examples – Part1 (basics, VDC and vPC)

For best article visual quality, open Nexus 7k – Getting Started Examples – Part1 (basics, VDC and vPC) directly at NetworkGeekStuff.

So I finally had a project with Cisco Nexus switches to finally get hands on experience on these boxes. I am no longer a fanboy of Cisco, so just practically, this article is a summary of my notes and example configurations that I have put together as a documentation for myself and now I will kind of share them with you. First of all, when I started writing this article it was November 2013 and Nexus 9000 were just released, note that this articles is based on Nexus 7000 series and not the new 9000 series. Sorry, not chance to get to 9000 yet, maybe later.

Cisco Nexu Thumbnail FINAL

Let’s get started. Similarly as with my previous IOS XR Getting Started Guide (part 1 and part 2), I will go over the very quick overview and then show basically a snapshots of configuring some elemental configurations. There is actually one advantage over the IOS XR in that the NX-IOS has and that is that it is more similar to the classical IOS we all know.

Basic commands to verify hardware, Continue reading

What is a “Best Practice”?

I see a lot of articles and even vendor whitepapers that like to throw the term “best practice” around like it’s pocket change. Truth be told, while there are plenty of general best practices that are recommended in any case, many of what a vendor will call “best practices” are usually just the most common response to an If/Then statement that represents the surrounding environment. Here’s a good example. I’ve heard on multiple occasions regarding the standard vSwitch in VMWare vSphere that it is a “best practice” to set the load balancing policy to “route based on the originating virtual port ID”.

What is a “Best Practice”?

I see a lot of articles and even vendor whitepapers that like to throw the term “best practice” around like it’s pocket change. Truth be told, while there are plenty of general best practices that are recommended in any case, many of what a vendor will call “best practices” are usually just the most common response to an If/Then statement that represents the surrounding environment. Here’s a good example. I’ve heard on multiple occasions regarding the standard vSwitch in VMWare vSphere that it is a “best practice” to set the load balancing policy to “route based on the originating virtual port ID”.

[minipost] Create a loopback hard-drive partition inside a file in linux

For best article visual quality, open [minipost] Create a loopback hard-drive partition inside a file in linux directly at NetworkGeekStuff.

TuxTIP_mergedThis article is really just a quick documentation for something that I do almost each year, and each year I must google-search how I did the last time. So from now on I will have it in my own notes …. here!

Mu current problem was that I have VPS system from a small provider hpcloud.com :) , but the base image is divided to 10 GB of system partition and another 20 GB of data partition. And as luck would have it, I needed 25 GB for data. One of the options was to buy more storage, but I have seen that my minimalistic debian hardly used more than 1,7 GB from the 10 GB system space and I wanted to make use of the remaining space.

Additionally, resizing the partition was not an option as this was the provider mandatory separation, so I decided to use a loopback file emulating a hard-drive.

What this means is that I will create a 5 GB file in the system partition, and mount it as a directory in the data partition, Continue reading

ArmA2 CWR2 mod: Winter Kolgujev + Malden Domination with Xmas extras

For best article visual quality, open ArmA2 CWR2 mod: Winter Kolgujev + Malden Domination with Xmas extras directly at NetworkGeekStuff.

Last year, I released quickly one nice modification to my custom Malden CWR2 Domination and despite being only announced really only on this blog and to few of my friends last year, I really enjoyed creating it. So this year I decided to put off some dust from it and also port it to a fully winter themed island of Winter Kolgujev from the latest CWR2 mod. Again, this is based on Xeno’s Domination and original port to Everon by OC, then customized on a scripting level with multiple features.

ThumbnailWinter

Features:

Christmas/Winter centric features:

  • Permanent SNOW FALL + FOG during the mission to have a deep atmosphere + in Malden also custom environment sounds, that is why the file is a bit bigger.
  • All CWR2 infantry units are using Winter camouflage (see pictures below, great work from CWR2 mod team to release this)
  • There are Christmas presents under a tree for your team, but be careful, if you fail to protect some girls in the base, you will loose the presents.
  • Custom Christmas carol music in intro + if you Continue reading

Hardware – Is SFP+ just a smaller version of XFP?

In the last post I discussed clock and data recovery (CDR). This post examines an application of re-timers (or CDRs) within XFP and SFP+ transceivers. I’ve previously covered the size, power and connector differences of 10G transceivers before, but this post will focus … Continue reading →

The post Hardware – Is SFP+ just a smaller version of XFP? appeared first on The Network Sherpa.

Project DEW

I don't want to claim myself as Global Consultant anymore. It seems like many people have problem with that. Some called me showing off, some said I'm too proud with that title. Others even said I spent so much time marketing myself. Blah blah. Ok, ok, I get it.

But here is the fact: since I joined Cisco in 2006 I've traveled to many countries to do consulting projects. Below you can see some Cisco customers in Asia, Europe, Middle East and Africa that I worked with in the past. And most of the time my role in the project is to lead the design work: to capture customer requirements and provide technical solution to address them. In many projects I also lead the implementation and migration. For some projects I'm responsible to lead the whole engagement from project scheduling, managing resources as well as quality assurance for deliverables. So call me anything you want, even Janitor, but it seems like I have some experiences working on design consultancy project, globally.


And actually before I joined Cisco I had already done many design project as well with many customers. I invented my own methodology and workflow for design work. Continue reading

Make sure you patch your holiday gifts

Let me start off with a question, what are the steps involved when it comes to giving someone a gift? Is it as simple as buy, wrap and handover? For the more traditional gifts like perfume this would be the correct answer but if you are giving electronic gifts then you may be leaving out […]

Author information

Darragh Delaney

Technical Director at NetFort

Darragh Delaney is head of technical services at NetFort. As Director of Technical Services and Customer Support, he interacts on a daily basis with NetFort customers and is responsible for the delivery of a high quality technical and customer support service.

Darragh has extensive experience in the IT industry, having previously worked for O2 and Tyco. His User and Network Forensics blog. for Computer World focuses his experiences of network management and IT security in the real world. In his current role Darragh is regularly on site with network administrators and managers and this blog is a window into the real world of keeping networks running and data assets secure.

He shares network security and management best practices on the NetFort blog. Follow Darragh on Twitter @darraghdelaney and NetFort Technologies @netfort. You can also contact him Continue reading

OpenFlow/SDN Won’t Scale?

I got in a conversation today on Twitter, talking about SDN/SDF (software defined forwarding), which is a new term I totally made up which I use to describe the programmatic and centralized control of forwarding tables on switches and multi-layer switches. The comment was made that OpenFlow in particular won’t scale, which reminded me of an article by Doug Gourlay of Arista talking about scalability issues with OpenFlow.

The argument that Doug Gourlay of Arista had is essentially that OpenFlow can’t keep up with the number of new flows in a network (check out points 2 and 3). In a given data center, there would be tens of thousands (or millions or tens of millions) of individual flows running through a network at any given moment. And by flows, I mean keeping track of stateful TCP connection or UDP pseudo-flows. The connection rate would also be pretty high if you’re talking dozens or hundreds of VMs, all taking in new connections. 

My answer is that yeah, if you’re going to try to put the state of every TCP connection and UDP flow into the network operating system and into the forwarding tables of the devices, that’s Continue reading

Video Series Examines SDN: The Good, the Bad, & the Ugly

Leading industry analyst and Packet Design CTO discuss all facets of SDN in short video casts

What’s the reality on the ground with software defined networking (SDN)? Are humans in the network becoming obsolete? What network management best practices can we bring to the automation realm? Packet Design has released a wide-ranging conversation on these topics and more between Jim Frey, vice president of research for analyst firm Enterprise Management Associates, and Cengiz Alaettinoglu, CTO of Packet Design. Titled “SDN: The Good, the Bad & the Ugly,” the series consists of seven short videocasts where both experts provide an overview of SDN, related technologies, standards initiatives, and management considerations.


 SDN Video Series Segments:

  1. Defining SDN: What is it exactly and how does it differ from “software derived networking” and “network function virtualization?”

  2. SDN Standards Bodies & Consortia: Who is actively working on SDN and which segment is lagging?

  3. What’s Working and What’s Not: What are the risks with SDN? Is Google’s success with their custom-built SDN a model for the industry?

  4. The Need for a Network Access Broker (NAB): How do we determine if an application deployed via SDN will not adversely impact other applications?

  5. Use Cases for the Network Access Broker: Continue reading

Switching to Linux for… Switches?

Like many folks out there, I’m following the rise of “whitebox switching”, and am interested to see if (and where) it takes off. There’s many players out there who are trying to pitch disassociating the software from the hardware, and quite a few hardware manufacturers that are offering various hardware platforms on which to run […]

Author information

Will Dennis

Will Dennis

Will Dennis has been a systems and network administrator since 1989, and is currently the Network Administrator for NEC Laboratories America, located in Princeton NJ. He enjoys the constant learning it takes to keep up with the field of network and systems administration, and is currently pursuing the Cisco CCNP-R/S certification. He can be found on the Twitters as @willarddennis, and on Google Plus.

The post Switching to Linux for… Switches? appeared first on Packet Pushers Podcast and was written by Will Dennis.

Podcast Planning – Got A Great Network Down Story?

Greg and I want to record a “Nightmare Before Christmas” podcast, where folks come on and tell us their most grisly, horrifying network down story. The idea is a relaxed show chatting around the holiday fire, telling war stories, and being glad it’s all over now. So…got a good story? Want to come on a […]

Author information

Ethan Banks

Co-host at Packet Pushers

Ethan Banks, CCIE #20655, has been managing networks for higher ed, government, financials and high tech since 1995. Ethan co-hosts the Packet Pushers Podcast, which has seen over 2M downloads and reaches over 10K listeners. With whatever time is left, Ethan writes for fun & profit, studies for certifications, and enjoys science fiction. @ecbanks
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The post Podcast Planning – Got A Great Network Down Story? appeared first on Packet Pushers Podcast and was written by Ethan Banks.

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