Andrey Mikhalchuk’s Blog

Many people are dreaming about consolidating all media files (video, music, pictures etc) in a single place. For some it is a huge full of DVDs, CDs and photos. Others buy hardware media servers and store all files in them. I chose a solution based on Archos 605 WiFi and a Linux Server running UPnP Media Server. Here’s how it works …

Last 12 months I was working on an interesting device that provides the network security features many companies and families are dreaming about. You probably already have heard about different threats out there like internet predators, viruses, spyware, dangerous websites, confidential information leaking from your business and others. Also you probably tried to find answers to questions like

• Is my office network used appropriately? Do people really use it for work and not something else?
• Are my kids safe in the Internet? Are their virtual friends really friends?
• Why is my internet so slow?
• Who in my network is using the internet most, when and what for?
• How can I prevent my children or employees from browsing inappropriate content, wasting time in chats or games?

Finally, you might want to get answers to the questions immediately and you don’t want to spend a lot of time configuring every single computer in your network, installing software and other techi stuff … So the answer to all those questions is one small box called MineStream Defender and here is what it can do …

You ran ./configure and got “configure: error: C++ compiler cannot create executables”. Here is how to fix it …

I was recently installing squid at home as a single caching proxy for all computers in my home network. The simple way is just running squid on your linux router as is and configuring every single browser on all computers in your network so they access internet using squid. That’s doable, but boring. The more interesting way is setting up transparent proxy so all your http traffic goes through squid automatically. I’m not going to explain how to setup the transparent proxy as there are tons of articles in the internet about that, for instance:

• http://www.cyberciti.biz/tips/linux-setup-transparent-proxy-squid-howto.html
• http://tldp.org/HOWTO/TransparentProxy.html
• http://www.deckle.co.za/squid-users-guide/Transparent_Caching/Proxy

The documentation is very straightforward, and has just one problem: it is outdated and doesn’t work with the most recent versions of squid. I’ve read several instructions and was always ending up with these error messages:

Here’s how to fix the problem …

I prepared a page with my favorite software review. Most (if not all) of the utilities are for free and I hope you will enjoy those useful tools.

WRT54GL router is not capable of controlling mechanical parts as is. So we need to add a communication port to it. This post describes how to do that. The complete outline of the routerbot project can be found in this post.

For our robot we will need the following parts and tools:

Somehow my kids became huge fans of different kinds of robots, starting from teleoperated planet explorers and ending with transformers. So I promised them to build a robot, and in a few days I ended up with this result which I’m pretty proud to share. It appeared that for $150 or less you can build pretty cool robot that is way easier to program then most robots out there on the market + its range is way larger then most toys have. Here’s how you can build your own inexpensive yet powerful robot…

Imagine you need to create say 10 disks with predefined partitions loaded with some software. The ideal solution would be automatic disk partitioning and copying the software to it. While copying files is an easy-to-do everyday procedure partitioning is a bit more tricky (really, just a little bit). Here is a quick trick that will allow you to partition disks quickly.

Uff that was tough one … If you decided to make your mail communications more secure you probably switched on SSL option in your mail client for POP3/IMAP/SMTP servers. There is a good chance you will get one of those errors that sound like

The server you are connected to is using a security certificare that could not be verified.
A certificate chain processed, but terminated in a root certificate which is not trusted by the trust provider.
Do you want to continue using this server?

I spent way too much time solving the problem because what was just annoying message in Outlook appeared to be serious problem in MacMail. It was not capable of working correctly with that problem. In addition to that I tried to solve the problem using Plesk 8.2 that was a mistake. It appeared that whatever you do with certificates in Plesk that doesn’t affect the mail. So here is the solution for the problem:

The AdSense-Deluxe plugin is just wonderful! I used Adsense Manager before and didn’t like the fact it uses old code for Google Adsense and I can do nothing about that. AdSense-Deluxe is way simpler and allows you to modify the actual code - very smart move. Unfortunately after installation it may report “Cannot load adsense-deluxe.php” when you try to add new ad block. Here is the fix to the problem.

When I used NFS first time 15 years ago on Sun it seemed to me the top of progress. And it really was at that time. So dealing mostly with samba during last few years I forgot how actually NFS works until a few days ago when I issued standard “mount server:/directory /mnt/subdir” and tried to compile a project. The performance was HORRIBLE. So I spent some time investigating how to improve NFS performance and found this solution:

When you need to implement a DNS master/slave relationship, you obviously can go ahead and edit named config files, but when you do next change to DNS configuration using Plesk most your changes will be lost. From the other side Plesk doesn’t provide slave server configuration at all! Here is the solution that works for me on Plesk 8.2

Sometimes, for security reasons, it is useful to disable pop3 protocol on a server, leaving users with necessity of using secure pop3 protocol (i.e. in outlook they will have to check “Use SSL checkbox”, otherwise mail just won’t work). The civilized method is of course just ask people politely to make changes to their settings, but frequently people just don’t have time to do so. This tiny hack will force them to do so, otherwise their mail just won’t come.

When your mail is not working it is important to know exactly what part is broken (so you know if you should go blame sysadmin or just check your mail client settings). Let’s simulate basic POP3 client using regular telnet (enter commands without quotes) in order to check if the POP3 is doing fine:

“553 sorry, that domain isn’t in my list of allowed rcpthosts; no valid cert for gatewaying”
There could be many things leading to the problem. One of them is client inability to authorize to SMTP server. Here’s a quick explanation of what happens and how the problem could be solved.

Despite the process of obtaining an SSL certificate for your website is not very difficult it may take you plenty of time, because the price of mistake could be rather high. I’d say you can loose hundreds of dollars if you buy wrong type of certificate or get it from wrong place. Here’s a quick overview of the process that will make your SSL cert shopping experience more enjoyable.