Brute Force Attack

What is brute force attack? Kindly provide me the detailed explanation regarding this issue. Moreover kindly provide me the remedies of this issue.

A brute force attack is one where you (or more usually a script) tries to gain access to a resource by repeatedly using different credentials.

eg. I might set a script going that tries to ssh into a server as root. The first time it tries the password 'a', the second attempt it tries the password 'b' and so on ... Computer's are very good at this sort of thing :-)

Normally though passwords are guessed based on a dictionary.

There are many types of brute force attack - it depends what you're trying to attack!

A normal prevention method is to only allow so many failed login attempts before a host is blocked and no more login attempts are allowed from that host.

Sometimes changing ports for services such as ssh is also a good way to combat theses types of attacks.