Many network engineers are also tasked with maintaining systems that provide network services, those things that make the network easier to use such as DNS and DHCP or management systems that perform useful things like monitor the network, collect flow data or bestow access to the equipment by acting as bastion or jump hosts.  In many instances, robust and high availability services run on UNIX, Linux or BSD systems for stability and reliability, so those that manage these systems need to be…

I firmly believe that blending disciplines is the way of the future in IT. I’ve rambled about it here at other venues and I’m vocal (some would probably say brash) about it on the twitters.  Be it Networking and System, Systems and Security, Programming and Networking, most of us that have been around any length of time already do it but now it’s happening out in the open and “DevOps”, a form of the hybrid IT worker, has seemingly become the BOTD (Buzzword of the…

I recently had the displeasure of dealing with a series of failed disks in my newly created ZFS based NAS.  I had cobbled together roughly 12TB of disk space and jammed them into an old PC, stretching the limits of the platform when I decided to go with ZFS.  I broke all of the rules, underpowered, single core PC, only a handful of GIG of non-ECC RAM, etc.  I’m sure storage guys are having a coronary after reading that, but it works for me and has minimal issues since I just relatively…

I am an absolutely huge fan of statistical and instrumentation data, especially when it comes to traffic analysis, visualization and baselining.  I’ve rambled on about the importance of it at every opportunity.  As a result of that, I have been doing work with netflow and netflow-like data for a fairly long time.  My first collector was the OSU Flow tools based stuff  back around 13 years ago.  From there I played with all kinds of netflow tools, both commercial and open source, finally…

Working on some MX series routers recently I encountered a problem I’d never seen before, essentially preventing the configuration from being committed:``` buraglio@rtr# commit check re0: error: could not open configuration database (juniper.data+)

I had the need to build a FlowVisor instance under CentOS.  Since nearly all of the docs I could find were for debian, I threw this together.  I utilized this GENI doc and the github docs as a simple reference.  This is the quick and dirty method I used: Install the prerequisites:``` sudo yum -y install ant eclipse java-1.6.0-openjdk.x86_64 git sudo yum -y groupinstall “Development Tools”

One of my biggest complaints about VMware is that it is an enterprise application. It has historically catered to the masses, which I completely understand, but those of us that aren’t a fortune 500 company are figuratively and operationally shoved into a corner and forced to find hackish ways of doing things to work around the enterprise nature. One really, really good example of this is OS dependency. I hated architecture dependencies back in the old days (x86, SPARC, PPC) and I…

As much as I like to think I automate everything, I’m pretty bad at writing code to make my life easier since it tends to take me longer to write the code and it tends to make be a bit grumpy (this is eomthing I’m fixing by learning as much code dev as I can during my limited spare time).  However, I like to think I can be fairly smart about working around my limited programming skills (think boba fett rather than jedi) by using the tools available to common folk.  Enter iTerm2. Last…

Jon Langemak has a great write up on building the OpenDaylight controller under CentOS. Since I’ll have to do this a bunch of times, I though tI’d take what he so generously put online and build a very rudimentary script for deploying ODC under CentOS. The prerequisites are that you already have an account and ssh key at the OpenDaylight GIT repo and that you disable SELinux. Here is the script:``` #!/bin/bash

I had been working, off and on, on a how-to for building the daylight openflow controller under CentOS.  Most openflow docs and dev are done under ubuntu or debian, and while those are both fantastic alternatives, there are a huge number of folks that will want or need to use RHEL or CentOS. So, seeing as that is the case, having someone be mindful of that is important.  When I saw the write up by Jon Langemak, I scrapped my attempt at a how-to since his was so much better. If you’re not…