What is a recursive DNS query?

One of the most important part of the Internet is the DNS; I guess that’s clear for everybody. DNS is a distributed database, the largest in the world but in — at least — one aspect is extremely vulnerable: recursive queries. We distinguish two type of DNS queries:

Iterative or non-recursive
Recursive

Each 13 root server is configured [...]

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Google server running cPanel

While setting up a web-server is not a big deal, cPanel makes the whole process so much easier. Seemingly, Google takes the advantages of this software, too. We already knew that Google uses the open-source and so-popular Apache web-server, most likely because it can be adapted to various situations and has the lowest footprint yet [...]

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Significant traffic drop on 30th of november or where did my traffic go?

If you rely on European traffic, I guess you observed, too, that on 30th of November a great per cent of your traffic has gone… well, nowhere, but the users couldn’t reach your site hosted in the US.
Before we figured out what’s happening, we followed the golden route to debug the issue, nonetheless to say [...]

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Ban IP on server level after a number of unsuccessful logins

This is a widely used function amongst the server managers. Depending on your system configuration, the server will ban the enforcer’s IP, either putting it in the firewall’s deny list or, on Linux servers with IPTables installed, will put the IP in the drop list.
To achieve this feature, the easiest way is [...]

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Restrict access to directory or domain by IP, using .htaccess

I don’t blah too much on this subject.
Basically, you can restrict or allow who can connect to your site or who can access specific directories using .htaccess .
Here’s the code to block one specific IP, I use 192.168.0.1 to block, you replace it with the IP you want to deny.

order allow,deny
deny from 192.168.0.1
allow from [...]

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Hotlink Protection using .htaccess made easy

This is one of the most used tricks by the webmasters who care about their allocated bandwidth. The code which controls what are domains where your images can show up is very short, 4 line that is.
As always, I provide the full code, then below it I explain everything.
To use this code, you have to [...]

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Filter your variables easily but like a pro!

How painful input validation is! Think about all the possible threats, combination of threats… think with the users’ mind. It’s a pain. And usually who can write scripts which filters effectively the user inputs is considered a pro, without hesitation. Just because it’s hard to do it.
Take the following scenario: you have a text-field which [...]

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Installing ImageMagick without headaches

This is simple: on windows systems you have the option to use the automated installer here, it’s neither complicated or hard to install. On Linux based systems I recommend to install it from source for obvious reasons like you know what’s installed, where, and if there was a problem, you can debug easily because the [...]

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Tightening PHP

OK, let’s see what’s my point of view on this subject. Please note that nothing I say is a must, probably others would do in another way what I did, many would do things better or less good.
First of all, I would like to say a “thank you” to all of those who I manage [...]

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Stop network flood in one step

Ok, two
First connect to your server’s private network using SSH and login as root. Your data center should provide you how can you do this, on Softlayer servers you have to create first a VPN tunnel to the Softlayer network then you can connect to the server’s private IP.
Usually a server has two [...]

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