NeDi and Observium are two of my favourites network monitoring tools. I do like to deploy both, they complete each other and since they’re free there is no need to choose. The only problem with the use of two tools is the integration…

Dear #Dalmooc, Unfortunately, I have to press pause for some time on my learning to tackle deadlines, wrap up teaching and evaluate my students and my teaching. Hopefully I’ll be able to catch up before the deadlines for the early competencies. We now return you to your regularly scheduled program, already in progress.…

Tables Generator will do a lot for you. Its most useful features are importing from .csv and merging cells. The Booktabs table style (alternative to default table style from the menu) looks a bit nicer and is “publication quality”…

This post was for the 2nd week of #DALMOOC A concept/process mash up of a map…

This post is addressing the first assignment/question for #DALMOOC Analytics use at this organization is largely focused on academic analytics, using the results of assessment of student learning to inform course, program and curriculum…

Today I’m introducing new version of rmongodb (which I started to maintain) – v1.8.0. Install it from github: library(devtools) install_github(“mongosoup/rmongodb@v1.8.0”) Release version will be uploaded to CRAN shortly. This release brings a lot of improvements to rmongodb: Now rmongodb correctly handles arrays. mongo.bson.to…

I’d like to consider myself as a self-directed, life-long learner. Rather, I would now after undergrad, grad school with a plethora of job related learning thrown in. I didn’t start that way, I had to learn…

On Monday night, I went over to the Data Science meet up in Oxford. Even though the parking ticket machines in Oxford don’t accept ‘new’ 5 or 10 pence pieces, despite both having been in circulation for over 20 years, it was a good night. Talks were on plot…

Switch configuration includes many tasks, some of them are just boring and error prone…

SQL relay in Cardiff is part of the wider SQL Relay UK family and is essentially a free, touring conference, targeted at DBA’s (especially MS SQL Server) and BI users. Fortunately for me, they also had an “alternative tech” track which suited my interests more closely…

Last week I had the opportunity to attend the first Wireless LAN Professionals Conference in Europe…

Over the summer, some of us here at UBC started a reading group based around Hadley Wickham’s book, Advanced R Programming. The goal was to compare our answers to the exercises and our impressions of the content…

A couple of days ago I did a planned software upgrade of an HP5406zl…

EARL London, September 2014 The slides for my talk at the first ever EARL Conference…

ES6 specification is being clarified every passed day! One of the key features of the new version of the language are the generators. Generators (a.k.a. semicoroutines) will play quite important role after they are being officially released. They could be used to simplify the asynchronous control flow of any JavaScript program (look at co)…

In this blog post I’m going to share how could be build WebRTC chat with React.js. Before we continue lets describe briefly what React.js and WebRTC are. The application from this tutorial is available at GitHub. React.js React.js is reactive JavaScript framework, which helps you to build user interface. Facebook states that we can think of React as the “V” in MVC…

Log analysis is important to both troubleshoot and understand network devices behaviour. Tail/less/grep are great tools that can help to filter and search hundreds or thousands lines of logs. If you prefer a GUI there are a couple of alternatives that can fit well…

Answer in short: Because different formulas are used to calculate the R-squared of a linear regression, depending on whether it has an intercept or…

where -s stands for “symbolic” (just ln would create a hard link) However, if you are not a complete UNIX guru, then trying to access your linked files is likely to produce one of these errors: No such file or directory OR Too many levels of symbolic links Remove symbolic links just as you remove…

This publication aims to provide a more theoretical overview of some of the AngularJS components in order to show you how the things you are already familiar with (like different Object-Oriented Design Patterns) fit in the picture. Link to the first part of the series. Link to the second part of the series…

In this post, we will use the new name, Odoo instead of OpenERP but the content and the examples are compatible with OpenERP 5.0, 6.0, 6.1 and 7.0 and of course with Odoo v8.0. There is no need to be worried, I will try to be compatible with the new version…

This publication aims to provide a more theoretical overview of some of the AngularJS components in order to show you how the things you are already familiar with (like different Object-Oriented Design Patterns) fit in the picture. Link to the first part of the series…

In the very last day of availability of the CCIE v4 350-001 written exam I’ve renewed my CCIE for a couple of years more: My plan was to recertify with another track - Wireless or Security - but life happens and I took the easy path and did R&S again. I’ve passed the same written exam 3 times…

The output file will have all of the variables that exist in the input file as well as the new_var. Add -O if your input and output files are the same (overwrite)…

If you find yourself using some commands always with the same flags, then it would make sense to define them as alieses, by putting them into your .bashrc file like this (log out and back in for it to take effect): _-color=auto _colours folders, executables and symbolic links. -a for qstat displays more information…

The flag for extracting variables is -v (followed by variable name(s) separated by commas): In case you’ve forgotten what the names of your variables are, do: -h prints headers only (and not the…

I’m switching to GitHub pages with Jekyll. There are several reasons behind my decision: Faster! - static HTML is much faster than my old WordPress blog…

In this series of blog posts I’m going to cover the paper I’m writing at GitHub. It aims to provide a bit more theoretical overview of some of the AngularJS components in order to show you how the things you are already familiar with (like different Object-Oriented Design Patterns) fit in the picture…

Wireless traffic packet capture is not easy as wired traffic. Linux and OSX have several solutions but if you’re stuck with Windows the first problem is to find a compatible adapter. My choice is AirPcap, fully compatible with Wireshark and very esay to install. Install and setup Download and install Wireshark and AirPcap drivers…

Hopefully this will prove helpful to…

Overview In this post I will compare the use and performance of dplyr and data.table for the purposes of “split apply combine” style analysis, with some comparisons to base R methods. Skip to the bottom of the post if you’re just interested in the benchmarks…

Wikipedia describes the singleton design pattern as: The singleton pattern is a design pattern that restricts the instantiation of a class to one object…

Networking is awesome but some tasks may be quite boring and repetitive. For new campus network installations a lot of time is used just to put a basic initial configuration template on switches…

Some time ago I’ve installed the new core switches for a customer: a couple of Nexus 7000, a couple of 5000 and twelve Nexus 2232TM, Virtual port channels, VLANs, Radius auth and so on.. all the usual configs a good network engineer does. Since the Nexus 5000 are connected to an iSCSI storage I’ve configured Jumbo frames…

The Setup I have known for a while that S3 and S4 dispatch carries a performance penalty, but I have never run into a situation where it is a glaring problem…

This means two things: I’m CCIE for over one year now I need to prepare again the written exam The last day to test the v4 edition is June 3, 2014, I’ve passed that exam twice so I expect a little effort to pass it…

I’ve been listening to podcasts for a while. Like most people I started with the juggernaut, This American Life, but quickly opened up my catalogue to other shows and ideas…

I guess in the end you might be asking the wrong question. Of course it is hard, building cars is hard, doing astrophysics is hard, playing the cello is hard. But here we are with hundreds of cars to choose from, new PhDs staring at the stars every night, and parents enrolling their children in music lessons…

With big money at stake it’s no surprise that professional leagues and individual teams are fully embracing the big data craze. Anything and everything “for the win” has been true for centuries…

Earlier this week an old friend of mine sent me a message outlining a request. In an effort to get back to his habit of drawing and creating he was reaching to a few of his friends for some inspiration and ideas. Simple premise…

Sometimes you want to test your application in environment closer to the real world…

Ten years ago I’ve passed my first Cisco exam: CCNA! What was supposed to be just a marginal skill for a junior systems engineer became both my job and my passion…

Why should I use JavaScript MVC, MVVM, MVP or simply MVW(hatever works for you)? When I talk with people, who are beginners/intermediate in JavaScript I’m often asked this…

In this blog post I’m going to show you how to build a VNC client using AngularJS and Yeoman. The source code used in the post is available at my GitHub…

At first sight AngularJS seems like a magical framework, which does some weird but awesome things like dependency injection, data binding only by setting a single property to the magical object named $scope and many other things…

I took advantage of my participation at Cisco Live 2014 to book a free Cisco exam IUWNE…

Last week I had the opportunity to attend Cisco Live in Milan. This is my second time at Cisco Live, I’ve been in London last year. Some people still doesn’t know what Cisco Live is…

The textbook is different. It really goes back a long way. I wrote a textbook on forecasting in 1998 and it became the biggest selling textbook on statistical forecasting in the world. My contract said I should get 5% of sales, but I actually got much less. Wiley (the publisher) had no costs apart from printing and marketing, and they did a lousy job in marketing…

Here is an overview of what is involved in getting your Laravel 4 apps authentication system to integrate with Get Satisfaction Fastpass for single sign on…

Many network vendors are publishing simulators to the community. A simulator can be a way to complete a training or can be used for a PoC…

As many other vendors HP has a fast track for people already certified with Cisco to achieve an HP certification skipping some basic exams…

IPv6 is the evolution that everybody know must be done one day but not today…

Since AngularJS does not provide any built-in features for using inheritance, in this blog post I’ll describe how the general JavaScript inheritance patterns can be applied to AngularJS components. Controllers inheritance First, lets talk about controllers…

In this blog post I’ll introduce you the new way of annotating services included in AngularAOP v0.1.0. First, why we need a new way for annotation? In v0.0…

Questo post e’ dedicato ai networkers iscritti al CUG di AreaNetworking…

I’m also really interested in statistical learning as a family of modeling techniques, a kind of fitting them together very well and forming a grammer of models. You can make a new model by joing things together, just like the grammer of graphics by which you can come up with a new graphic that is just a new arrangment of existing…

I’m not a network security specialist but sometimes I’m curious about some topics and I like to test how they work…

In November 2013 I had the opportunity to work with the Australian Science Media Centre (AusSMC) and produce a talk explaining numbers and statistics. The deal was that it was 11 concepts on numbers and stats in 20 minutes. The concepts being: This was my first time ever really seriously teaching anything to…

In this blog post I’ll tell few words about the course Advanced JavaScript which Georgi Penkov, Evgeni Kunev and me are leading this semester in Sofia University…

Today I created a GitHub repository which contains a set of good practices and style guides for AngularJS application development. Its main goal is to be community-driven and to concentrate all the best practices for AngularJS development in one place…

This blog post is concentrated about web performance. I’ll skip the well known stuff about combining images into sprites, inlining images, DNS pre-fetching, combining and minifying script files, gzipping and so on…

Today, 10 years ago, I’ve registered this domain. My initial idea was just to have a place to play with html and to save some interesting links. After that I switched to RapidVeawer mostly beacuse I liked the themes and it was a good WYSIWYG editor. The current release is just another wordpress blog but it works for me…

Sometimes people are fond of saying: I think that this is the equivalent of saying: …What I am saying is true because of my argument. And statistics… The same goes for statistics, you could perform a variety of tests to support a particular point. The reader also has a responsibility to evaluate their use of tools to construct and support their…

Today I’ve passed 642-874 ARCH exam that in conjunction with CCIE and CCNP entitles to obtain the CCDP certification. To prepare the exam I’ve used the official study guide along with the documents in the Cisco Design Zone…

In this quick blog post I’ll show you how to create a simple VNC client in about 200 lines of JavaScript. For our goal we’re going to use only HTML5 and JavaScript (client and server side). The end result will be something like this: So, let’s begin! Our application will have very simple architecture – a proxy server written in Node.js and a client in HTML5 and JavaScript…

Today, I take my first shots at ranking Major League Baseball (MLB) teams. I see my efforts at prediction and ranking an ongoing process so that my models improve, the data I incorporate are more meaningful, and ultimately my predictions are largely accurate. For the first attempt, let’s rank MLB teams using the Bradley-Terry (BT) model…

In the following blog post I’ll write few words about what is Aspect-Oriented Programming, why I think it will be useful in AngularJS and I’m also going to give you a short tutorial for using a simple AOP framework I’ve developed. First things first…

Huawei network devices are becoming more and more popular in european market lately. It all started with 3G adapters, then mobiles, and now I see routers and switches deployed in many locations…

Lately, I have been working with finite mixture models for my postdoctoral work on data-driven automated gating…

There are a lot of explanations of Monte Carlo approximation out there. Here is one that worked for me. A famous mathematician named Stan Ulam liked solitaire. He wanted to work out the probability of getting a perfect solitaire hand. Being a mathematician, he also wanted to work this out analytically. The more trial simulations (iterations) you run, the better the…

Console access to devices for a network engineer is almost as important as telnet/ssh access…

Wikipedia says: “Analytic Solution” I find that such a definition relies on the reader knowing what the words ‘closed form’, ‘known functions’ and ‘constants’ are. So here’s my definition: “Analytic Solution” A solution where everything needed to solve a particular question is presented clearly and logically, with all assumptions defined. Waddaya…

It seems a strange thought at first. How do the humanities help you make money? You know, getting you a job. We’ve all got that annoying uncle or in-law or friend who plays devil’s advocate (or douchebag) when you reveal that you are studying French and…

One of the more annoying things of the windows command line is the lack of Shift+Ins to paste the clipboard. A bit of googling made me discover a very useful software called AutoHotkey…

Quite often I have to debug a wireless client roaming across lighweight Cisco APs to confirm it moves between APs as expected in the network design. On the WLC the command is “debug client MAC”…

As you know because of the SIMD nature of the GPU it’s extremely good for graphical calculations. Since HTML5 and CSS3 are here we have a couple of ways for efficient and smooth animations one of them are the CSS3 transitions…

Got mail from…

Before few months I was invited by Telerik Academy to make a talk about JavaScript. Last Monday Marian Kostadinov, Radoslav Georgiev and me made a whole seminar about the topic…

This post is inspired by my answer at StackOverflow. So why we should use publish/subscribe? Why it is useful? Is it making our work harder or it makes our application better? And the answer..…

I work with WiFi more than I admit to myself and now that I have more time to study outside the CCIE R&S blueprint boundaries it’s time to focus on other…

My home network is connected to the Internet via radio bridge…

In really enjoyed to read all the blog post of people passing the CCIE lab exam over the years. I’ve found the stories very inspirational so now it’s time for me to give back…

I noticed that not everybody knows how to download Cisco certs PDF files or order additional printed copies. Just open this link, login with your Cisco credentials and enter the menu “Certification Fulfillment”. An additional CCIE plaque costs 150USD, paper certs cost 15USD.…

I’ve passed the CCIE R&S lab exam yesterday in Brussels, results arrived this…

Cisco icons are globally recognized and generally accepted as standard for network icon topologies. You may use them freely, but you may not alter them…

Cisco stopped to publish CCIE statistics some time ago but in Cisco Live presentations we can find some slides like this:

A couple of days ago on twitter Bob McCouch who passed his lab on February 21st posted this:

I know 14 days are not enough to make statistics, but let’s play with the numbers since they’re very…

NTP client / server with authentication SERVER CONFIG ntp authentication-key 1 md5 0802657D2A36 7 ntp master 5 CLIENT CONFIG ntp authentication-key 1 md5 1531223F2705 7 ntp authenticate ntp trusted-key 1 ntp server 10.0.12…

Cisco Live! Europe: I’m in! First time here, the impression is like being in the Willy Wonka chocolate factory with the big difference you can touch everything without disappear. As my job is not focused on a single technology I’m registered to many different sessions, from WiFi to Security, from FCoE to Routing/Switching. A longer review will follow…

This article is about the functional concepts of JavaScript. Some of them are built-in the languages, others extra implemented but all of them are very common for purely functional languages like Haskell. First I want to tell what I mean with the term purely functional language…

plainvm can take the virtualization into different level of usage. To prove this I’ll first ask few rhetorical questions and put their answers..…

Much of my research in machine learning is aimed at small-sample, high-dimensional bioinformatics data sets. For instance, here is a paper of mine on the topic. A large number of papers proposing new machine-learning methods that target high-dimensional data use the same two data sets and consider few others…

For good or ill, we crossed the end of the world predicted by Mayans and were pushed back to a tough world. It’s time to move forward. Data analysis, as I understand it, is not a fixed set of techniques. It is a way of life, and it has a name: curiosity. There is always something else to find out and something more to learn…

The dscp mutation map is a per-port configuration that permits to modify the dscp field of a packet…

Netflow quick notes for basic config. NETFLOW EXPORT Send NetFlow data to a collector: From? (source) Where? (destination, port) How? (udp, sctp, backup) Version? (1,5,9) SAMPLING / FILTERING Not all traffic is evaluated to generate NetFlow statistics…

Your Route to Cisco Career Success by Kevin Wallace A free ebook from Amazon/Kindle about the strategy to prepare for a brilliant career in networking…

A few days ago, I’ve created a GitHub repository. It’s main goal was to collect different algorithms with implementations in JavaScript. I started with basic ones – sorting (insertion, selection, bubble sort..). After that I implemented few “more advance” like marge, quick and heap sort…

Recently I started playing with Kaggle. I quickly became frustrated that in order to download their data I had to use their website. I prefer instead the option to download the data programmatically. After some Googling, the best recommendation I found was to use lynx…

After one week of training in Milan and passing the exam I’ve added an Alcatel-Lucent certification to my c.v.: “Alcatel-Lucent Certified Field Expert - ACFE - OmniSwitch R6/R6” OmniSwitch have some proprietary features, like mobile vlans, that may be very useful in some deployments…

My daughter is always asleep in bed when the local badger comes around. So we built a badger-cam to attempt to get video footage of our visitor. This is from the second night of filming. The camera is mounted inside an unused cat flap and the large shape dominating the top half of the picture is the flap itself, which had slipped down from the first night…

I haven’t wrote here for a while so I decided to write about something more practical. Actually the idea for the post come from one my response in stackoverflow…