I am very impressed and interested in e-learning and open source moodle. Moodle is the best open source e-learning program and has became the best software because it is used by thousands schools, universities, and institutes from all over the world.
I just found a website which is discuss about e-learning and moodle as the best open-source LMS. To access it, you just need to open www.muhaiminabd.com
All articles on MuhaiminAbd are written only in two languages, English and Indonesian (70% Indonesian and 40% English) but it has a widget named Google Translator. So that, visitors can use that widget to translate all articles into their own language.
The second advantages is, information that are written on that site are explained with pictorial exmpalanion. So, once you feel confuse, you can see a picture or some to guide you to follow the right tutorial.
DOS is one of the attacks that were encountered in the networking world today. You never know when this will be under attack. DOS attacks can happen anywhere on the network and can be addressed to anyone, even to the personal. However, usually the most commonly affected are the big servers like Google, Yahoo, and banking which directly provides services through a network. If you decide to provide networking services over a network, you also must be ready to bear the risk, one of them is DOS attack.
These attacks are usually aimed to shut down the computer or network services from being attacked. The impact will be huge for companies or agencies that provide services primarily to banking. Victims of this attack will not be able to provide good service as usual. Because, this DOS attack works as a barrier or even be able to stop the service on a system.
Basically, DOS attacks are difficult to detect, unless the attacker has made several experiments with the same IP address. It would be very easy to block it. DOS may be difficult to overcome because of the attack is related to the service, a system with high security levels are usually low to provide comfort to users. Imagine if Google used as an intermediary server to attack, would be very confusing for administrators at an internet service provider. Administrators can not be home to block IP addresses from Google because that will be affected is the user's internet service. It is necessary to find the right solution by the internet provider.
When someone wants to do a DOS attack, there are lots of ways you can do. Classification of DOS attacks including "syn attack" and "UDP flood". Current DOS attacks again the impact is not too big because the network has many experts find the latest security methods and patching a system.
DOS attack is not a difficult thing to do, but if the attacker wants to give a great impact, it takes knowledge and adequate resources to do so. observations about the target are also things that should not be forgotten. Addressing directly the DOS can be done by turning off the service being attacked or by turning off the server, but doing so will result in another user wants to access that server.
Source: DOS (Denial of Services)