Teamviewer on mobile: "Not ready. Please check your connection"

By YellowOnline on Wednesday 20 April 2016 22:44 - Comments (2)
Category: Networking, Views: 4.008

Usually this is your firewall blocking traffic, like here on one of my Sophos UTMs:

The solution is, obviously, to allow outgoing traffic 5938/tcp. Or not use Teamviewer: Remote Control.

Actually I was looking for a way to control Windows Phone over Teamviewer. I use it to support Android devices already - some read only, but that's still better than nothing - but for Windows Mobile (or as a Continuum Application) it doesn't seem to be available yet sadly.

DIY Firewall: Sophos UTM: The Basics

By YellowOnline on Saturday 7 November 2015 14:05 - Comments (15)
Categories: Hardware, Networking, Views: 20.509

Warner Bros extorted €1 000 from me a while ago because of a 3 second upload of Vampire Diaries - that rubbish, of all things ... - from my network. If I wouldn't pay, they threatened to sue me into bankruptcy for the rest of my life with their army of lawyers.

I hope to have my revenge on them, or at least on the bloodhound lawyers they send to me, one day; but in the meantime I just want to avoid this very unfortunate episode from happening again.

Looking for a way to block torrents on my network, that includes myself, my visitors and most of my neighbours, I decided to install a real firewall.

Firewalls are expensive. We're not talking about a software application blocking traffic on specific ports on your computer, but about a dedicated hardware device capable of analyzing in real time all traffic going over it. Most of these devices cost upwards from €500 or even €10 000+, depending whether you need a SOHO product or a full-blown enterprise level firewall. And all of this needs an expensive yearly license on top of the hardware

So what options do "prosumers" have? Well, the Sophos UTM seems to fill that gap. Sophos sells its own hardware for the SOHO market, but made the software free to download plus gives you a full license for up to 50 users for free. That also includes their antivirus for up to 12 users.

Basically, you can build your own hardware, install their image and have a professional, highly customizable firewall with free antivirus on top of it for free. I'm skeptical about altruism from big companies, so I wonder what their long-term strategy is. Getting a bigger share of the market? Anyway, for the time being, this is an unbeatable deal. For protecting my own 5 devices plus server with ESET I paid €200 last year - the server license is 75% of that price. For half the price in hardware as a one-time investment, I've got a lot more bang for my bucks now.

A short overview of its advantages and disadvantages:

  • Full network control
  • Options galore, including your own VPN
  • Dirt-cheap
  • Very documented and community-supported (Astaro forums)
  • You'll need to be knowledgeable about networking or at least ready to invest time in it
  • Expect a performance hit, depending on hardware
  • Wifi not directly manageable, except if you use Sophos Wifi (€€€) - but you can just connect an AP of course
Talking about hardware: the hardware you need for your own UTM can be as heavy as you make it. I kept mine light for both financial and ecological reasons; and because I seldom expect more than 10 concurrent users. Still, a minimal machine will cost you about €300 in parts. Fortunately, I found a great deal on e-bay.

More on my hardware and a step by step guide for getting the Sophos UTM's basic functions working right away. Before continuing, however, be aware that this page contains about 50 (resized) screenshots and you might consider twice before opening it on your mobile phone. :)

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Migrating the Windows DHCP role between languages, versions and architectures

By YellowOnline on Monday 26 October 2015 11:38 - Comments (2)
Categories: Networking, Windows, Views: 12.801

I'm moving a lot of DCs from Server 2003 to Server 2008 R2. The original machines are in Dutch, French, Spanish, Italian, German and Polish - but I want the whole backend to be in English. The following procedure worked out fine, even though it is not for the faint-hearted. I did one move to Server 2012R2 as well this way, so it isn't limited to 2008 R2.

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Wifi: Slow download but fast upload after changing router

By YellowOnline on Sunday 21 April 2013 22:18 - Comments (15)
Category: Networking, Views: 6.300

Wifi is a technology I barely use. Old-fashioned as I am, I stick to cables; if only because I have a great internet connection that I can't fully use over wireless (not even mentioning latency for gaming). Pro info:

But this article isn't to brag about my connection - and I'm sure there are people who have an even better one - but to point out a problem I noticed with Wifi that took me an hour to find out, fiddling with all settings on my router.

This article applies at least to the Netgear CG3100L (EuroDOCSIS 3.0, Gigabit, 11b/g/n), but might also apply for other brands and models. Because this model is the new one distributed by Numéricable in Brussels, Luxembourg and France, this post will also be in French.

Cet article s'applique au moins au Netgear CG3100L (EuroDOCSIS 3.0, Gigabit, 11b/g/n), mais pourrait également s'appliquer à d'autres marques et modèles. Parce que ce modèle est la nouvelle distribuée par Numéricable à Bruxelles, Luxembourg et en France, ce post sera également en français. D'habitude on ne voit pas de français sur mon blog - sauf une article sur Gainsbourg récemment - donc soyez heureux que je fasse cet effort :)

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