Author Archive

Ingmar Verheij

Ingmar Verheij works as a SE at Citrix Systems Inc. All written content is my own opinion, not my employers.

I built a smart heat recovery system!

Written by Ingmar Verheij on December 24th, 2017. Posted in Other

Begin 2015 I’ve started on my first IoT project; building a smart heat recovery system (or warmte terugwin unit – WTW). Back then I wrote an article (in Dutch, see here) explaining why I felt this was necessary and my initial approach. I never could have expected the journey I started, I had opened Pandora’s box.

I must admit it has been a fun ride with many ups and some downs (otherwise there would have been no ups)! I’ve learned so many things, ranging from hardware design, PCB’s, software coding and the IoT ecosystem in general. Mainly it’s been a journey refreshing my memory, some things I haven’t done since I was 17 and I was eager on learning it again.

In this article I want to share with you the result of *almost* 3 years of learning; my IoT project is finished

SSO to ShareFile with Unified Gateway

Written by Ingmar Verheij on January 8th, 2016. Posted in Netscaler

ShareFileWith the release of NetScaler 11 the Unified Gateway feature became available. Besides that the Unified Gateway enables companies to create a single point of entry for different types of connection (from full blown VPN to ICA proxy and everything in between) it also comes with a landing page where users can access their (SaaS) applications. This is a great addition to the (already long) list of use-cases for a NetScaler in your network.

Now if there’s something users hate than that’s doing things more than once. So when companies make the (ow so logical) transition from “legacy” Windows applications to SaaS applications, so they no longer have to care about how that application works / runs / updates, the end-user is faced with a number of new challenges:

  • Where can I find that new SaaS application?
  • Why do I have to logon again?
  • Why do I have multiple passwords (that change on different moments)?

This is where the Unified Gateway comes into play, it offers a useful landing page where users can find their applications (hey that sounds familiar!). And since the industry made SAML the de-facto standard for authentication to SaaS applications, that might solve the other two challenges!

Long introduction to why I wanted to write this blog, but here’s how you can achieve a Singe Sign-On (SSO) experience from the NetScaler Unified Gateway to ShareFile using SAML.

I don’t care-as-a-Service

Written by Ingmar Verheij on November 15th, 2015. Posted in Cloud, Geen categorie

I dont care as-a-serviceAfter many years of making fuzz about Cloud, it’s happening. Cloud is hotter than ever and companies are now seriously considering to change their strategy. Some choose a “Cloud where possible” strategy where others go for a “Cloud unless” approach.

So what is it that makes companies are so focussed on Cloud (after the industry hyped this for many years)? IMHO there’s a very simple reason: they don’t care about technology because they don’t want to care.

And you know what? It makes sense. Companies run a business, they provide services to their customers. They’re not an IT shop, they need IT to drive their business. This is a fundamental statement I’ve heard throughout my entire career told by every customer.

Companies don’t care how IT does it, it just needs to work. They need a service.

And there you go, there’s the one reason companies are moving to “Cloud”. Or better, they’re consuming services from other companies that specialised in that service. IT departments had their chance, for many years, to help businesses. They failed, miserably, over and over again.

Bediening WTW, altijd op de verkeerde plek?

Written by Ingmar Verheij on January 31st, 2015. Posted in Other

Brink 4 standenschakelaar

Sinds een jaar of twee woon ik een nieuwbouw woning waarin een WTW (warmeterugwinunit) zit om het huis van frisse lucht te voorzien en energie te besparen. Zo’n WTW installatie kan met behulp van een schakelaar in verschillende standen worden gezet. Sommige schakelaars zijn tevens voorzien van een indicatie-led voor het vervangen van de filters (dit is bij mij ook het geval).

Het idee van de standen is eenvoudig: 1 – ik ben op vakantie (laag) , 2 – ik ben thuis (normaal), 3 – ik kook / douche (hoog). Oftewel, als je gaat koken / douchen dan wordt er aangeraden om de schakelaar tijdelijk (30 min) in stand 3 te zetten. Nu vind ik koken discutabel wanneer je een afzuigkap hebt maar voor douchen valt iets te zeggen, het wordt immers best vochtig in een huis (waarin geen ventilatieroosters zitten).

Update 7-2-2015: Componenten besteld, eerste resultaten luchtvochtigheid en accu (zie onderaan).

Update 16-10-2017: PCB met componenten (rev 0.1) en interface gebouwd


Mijn dilemma

Ietwat onhandige locatie voor een schakelaar...Waarom zit deze schakelaar ALTIJD op de verkeerde plek? In de meeste huizen zit de knop OF in de keuken OF in de badkamer. In mijn geval is de locatie van de knop nog iets aparter, hij hangt naast de WTW-unit (op zolder, in een kast)… Daar ben ik overigens pas na 2 jaar achter gekomen (en dus ook dat er een indicatie-led is voor het vervangen het filter).

Zit de knop in de keuken dan moet je naar beneden als je gaat douchen en als de knop wel in de badkamer zit dan moet je eraan denken om de knop van 2 > 3 te zetten en na 30 min weer van 3 > 2. Dat laatste is probleem, maar als IT’er ben ik van nature lui aangelegd (“dat kan beter”).

One Content Switch to rule them all!

Written by Ingmar Verheij on August 17th, 2014. Posted in Netscaler

One content switch to rule them allThe Content Switch (CSW) is a beautiful feature that enables you to use a single point of entry – your NetScaler – to host multiple services (like XenDesktop, XenMobile and Sharefile). Based on the content (and context) requested the CSW will direct the traffic to the server offering the best service suitable for the task.

Since I visit sites that restrict outgoing traffic to known ports (sometimes only port 80 and 443), and only have a single IP in my home lab, I needed a solution that allows me to demo several Citrix products using the same entry point. In this article I’ll show you how you can use the CSW to host several Citrix products (XenDesktop, XenMobile and ShareFile) using a single IP and port.

Disclaimer: Parts in this setup are not supported and therefore shouldn’t be used in production environments!