PHP and MySQL Web Development 4th Ed-tqw-_darksiderg

Computer and Operating System Security
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DMZs have two major advantages:
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They protect our servers and web applications from internal attacks as well as
external attacks.
They protect our internal networks even further by putting more layers of firewalls
and security between our corporate network and the Internet.
The design, installation, and maintenance of a DMZ is something that should be coordinated
with the network administrators for the location where you will be hosting your
web application.
Prepare for DoS and DDoS Attacks
One of the more frightening attacks seen today is the denial of service (DoS) attack,
which we mentioned in Chapter 15. Network DOS attacks and the even more alarming
distributed denial of service (DDoS) attacks use hijacked computers, worms, or other
devices to exploit weaknesses in software installations, or even those inherent within the
design of protocols such as TCP/IP themselves to swamp a computer and prevent it
from replying to any connection requests from legitimate clients.
Unfortunately, this type of attack is very difficult to prevent and respond to. Some
network appliance vendors sell equipment to help mitigate the risks and effects of DoS
attacks, but there are no comprehensive solutions against them yet.
Your network administrator, at the very least, should do some research to understand
the nature of the problem and the risks that your particular network and installations
face.This, in combination with discussions with your ISP (or whomever will be hosting
the machines running your ISP) will help prepare you for the eventuality when such an
attack does occur. Even if the attack is not directed specifically at your servers, they may
end up being victims nonetheless.
Computer and Operating System Security
The last thing we will worry about protecting is the server computer on which the web
application runs.There are a few key ways in which you can and should do this.
Keep the Operating System Up-to-Date
One of the easier ways to keep your computer safe is to keep the operating system software
up-to-date as much as possible. As soon as you choose a particular operating system
for your production environment, you should set into motion a plan for performing
upgrades and applying security patches to that operating system.You should also have
somebody periodically go and check certain sources looking for new alerts, patches, or
updates.
Where exactly you find out about vulnerabilities depends exactly on the operating
system software you are using.Typically, this can be done from the vendor from which