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This blog is the first in a planned series, aimed at describing how some of the current SDN offerings (NSX, DFA, and ACI) work from a practical perspective. I'll explain the title in a moment.  (Updated 1/7/14.) Concerning this blog series: I'm a networking person, so I want to know…

There's a new Cisco IWAN blog containing some good IWAN links. I'm mentioning it here in case you missed it, perhaps due to year end avoidance of online activities, busy-ness, etc. Also as followup to my prior IWAN ("Intelligent WAN") blog, IWAN, Cisco, and Akamai (Oh My!). In case you want the…

I've been trying to blog about NSX, DFA, and ACI for a while. I'll blame Cisco -- they're now coming out with additional info. And I kept coming up with more Things I Don't Know. Hence, deferred blogging, to avoid putting an ignorant foot in my mouth. I'm now equipped…

I’ve been thinking about the types of network abstractions that SDN might enable ever since I saw Scott Shenker’s Gentle Introduction to SDN. In that presentation Scott said that we [...]

It is no secret that I am interested in network management. Every time I start working in a large network, I get frustrated with the lack of tools to see [...]

I just posted a blog at nojitter.com titled Monitoring a Software Defined Network, Part 1. In it, I discuss the basic network monitoring functions that will be needed. Most of these [...]

Well, now that some time has elapsed, I have some more thoughts -- after-thoughts -- about Application Centric Networking (#ACI). And I'd like to share them. I include some thoughts about VMware NSX for comparison. (#NSX). For those who missed my prior blogs about the ACI Launch: The Cisco ACI Launch,…

This is the second of at least two blogs about Cisco Application Centric Infrastructure (ACI). The first covered the broad set of announcements with a focus on the hardware, and can be found at https://netcraftsmen.com/blogs/entry/the-cisco-insieme-aci-launch-part-1.html. It contained a set of links about ACI and the launch. This one focuses more…

I'm writing this at and after the Cisco / Insieme #ACI (Application Centric Infrastructure)  launch today in New York City. There's much to cover! Recall that in some prior blogs I threw out a bunch of guesses in a prior blog, and a couple of things I hoped for. I'm…

If you think about it, one problem in networking is that there are too many applications, and too little time. I greatly enjoyed a recent blog by  @RealLisaC, seasonally titled The Ghost of Application-Aware Networking. Excellent reading! It can be found at http://theborgqueen.wordpress.com/2013/10/29/the-ghost-of-application-aware-networking/. The following blog represents various thoughts that it and my…

This is just a short post inspired by one of my colleagues. He wanted to know how to tell whether a Nexus 5548 contained a Layer 3 I/O module or a Layer 2 I/O module. It's pretty easy, I told him - use the show module command. L3-5K2# sh module…

I keep seeing use case discussions where SDN magically solves bandwidth problems. I am very interested in them. I do wish the authors would take the time to explain the network topology and their assumptions. Frankly, this does not add up for me, at least not without some additional information.…