DOS (denial of service) caused usually a temporary interruption of a hosting service Vietnam on the Internet.

This attack is dangerous actions that make sever or network resource are not available to users.

The most popular denial of service attack is related to significantly increasing access even to top hosting Vietnam at the same time. In a DOS attack, a computer or an Internet connection will be exceed use because of bandwidth will overload by many connecting request from the outside. Overloading causes hosting resources cannot meet the legitimate traffics.

A particular computer, a port or a system service, a network component or even the entire network can become targeted resources to a DOS attack. DOS attacks can also target to the communication between people and systems by disabling the alarm, printer, phone and computer matters. It is the same to other resources include computing resources (bandwidth, disk space, processing time); configuration information (routing information); status information. Moreover DOS attacks make the server hosting Vietnam system management disable; exploit vulnerabilities operating system and make errors in physical computer face to a state of instability.

DOS attack is cheaper and easy to make and you can get difficulty to handle without the suitable tools. This makes DOS extremely popular even with those who are not professional. In fact, DOS attack services provided by some bad-websites can be bought by $50. These services are increasingly day by day and become more complex. These malware can efficiently exploit application vulnerabilities and avoid firewall detection.

DOS (denial of service) attack is when a targeted server is attacked by a single server meanwhile DDOS attack means distributed denial of service attack. The hacker will attack another target server by using the multiple servers. With this DDOS, the attack will be distributed through multiple servers. Traffics that are associated with single DDOS attack can come from a large number of compromised PCs or servers. DDOS attacks are using a lot of devices and Internet connections, often globally distributed by botnet systems. So DDOS attacks are often so difficult to handle and web hosting in Vietnam was attacked by requests from hundreds to thousands of different sources. These bellows is popular types of The DDOS attack:

• Attacks network bandwidth

This includes UDP floods, ICMP floods and other spoofed-packet floods. The objective of the hackers is overwhelming the bandwidth, and intensity is measured in bits per second (Bps).

• Attacks protocols

This includes SYN floods, fragmented packets, ping of death, Smurf DDOS. This attack runs out of server resources or the intermediate communications devices such as firewalls, loading balancing; packets per second measurement unit.

• Attacks the application layers

This includes Slowloris attack, Zero-day DDOS, vulnerabilities apache attacks, Windows or OpenBSD attacks. The purpose of hackers is to make the web server disable.

The best web hosting in Vietnam can also get DOS attacks. However, the rapid detection can prevent your hosting from DOS attacks. The first thing to do is to effectively and rapidly detect flow of malicious input. When traffic DOS attacks have been identified, the first step is setting an expanded infrastructure to handle attack until the malwares are prevented. DDOS attacks cannot be predicted in advance, but there are a lot of great and effective tool that help minimize the influence of this attacks.