วันศุกร์ที่ 12 กุมภาพันธ์ พ.ศ. 2553

Home Network Security

This document gives home users an overview of the security risks and countermeasures associated with Internet connectivity, especially in the context of “always-on” or broadband access services (such as cable modems and DSL). However, much of the content is also relevant to traditional dial-up users (users who connect to the Internet using a modem)

# Computer security

1. What is computer security?

Computer security is the process of preventing and detecting unauthorized use of your computer. Prevention measures help you to stop unauthorized users (also known as "intruders") from accessing any part of your computer system. Detection helps you to determine whether or not someone attempted to break into your system, if they were successful, and what they may have done.
2. Why should I care about computer security?

We use computers for everything from banking and investing to shopping and communicating with others through email or chat programs. Although you may not consider your communications "top secret," you probably do not want strangers reading your email, using your computer to attack other systems, sending forged email from your computer, or examining personal information stored on your computer (such as financial statements).
3. Who would want to break into my computer at home?

Intruders (also referred to as hackers, attackers, or crackers) may not care about your identity. Often they want to gain control of your computer so they can use it to launch attacks on other computer systems.

Having control of your computer gives them the ability to hide their true location as they launch attacks, often against high-profile computer systems such as government or financial systems. Even if you have a computer connected to the Internet only to play the latest games or to send email to friends and family, your computer may be a target.

Intruders may be able to watch all your actions on the computer, or cause damage to your computer by reformatting your hard drive or changing your data.
4. How easy is it to break into my computer?

Unfortunately, intruders are always discovering new vulnerabilities (informally called "holes") to exploit in computer software. The complexity of software makes it increasingly difficult to thoroughly test the security of computer systems.

When holes are discovered, computer vendors will usually develop patches to address the problem(s). However, it is up to you, the user, to obtain and install the patches, or correctly configure the software to operate more securely. Most of the incident reports of computer break-ins received at the CERT/CC could have been prevented if system administrators and users kept their computers up-to-date with patches and security fixes.

Also, some software applications have default settings that allow other users to access your computer unless you change the settings to be more secure. Examples include chat programs that let outsiders execute commands on your computer or web browsers that could allow someone to place harmful programs on your computer that run when you click on them.

Following issues.

วันอังคารที่ 9 กุมภาพันธ์ พ.ศ. 2553

wireless access points and routers

Nearly all wireless access points and routers allow an administrator to manage their WiFi network through a special administrative account. This account provides complete "superuser" access to the device's configuration utilities with a special username and password.
Manufacturers set both the account username and password at the factory. The username is often simply the word admin or administrator. The password is typically empty (blank), the words "admin," "public," or "password," or some other simple word.
To improve the security of a Wi-Fi network, you should change the administrative password on your wireless access point or router immediately when installing the unit. The default passwords for popular models of wireless network gear are well-known to hackers and often posted on the Internet. Most devices do not allow the administrative username to be changed, but if yours does, seriously consider changing this name as well.
Finally, to maintain home network security in the future, continue changing this administrative password regularly, not just one time. Many experts recommend changing passwords every 30 to 90 days. Use words that would be very difficult for others to guess.
Wireless access points (APs or WAPs) are specially configured nodes on wireless local area networks (WLANs). Access points act as a central transmitter and receiver of WLAN radio signals.
Access points used in home or small business networks are generally small, dedicated hardware devices featuring a built-in network adapter, antenna, and radio transmitter. Access points support Wi-Fi wireless communication standards.


Although very small WLANs can function without access points in so-called "ad hoc" or peer-to-peer mode, access points support "infrastructure" mode. This mode bridges WLANs with a wired Ethernet LAN and also scales the network to support more clients. Older and base model access points allowed a maximum of only 10 or 20 clients; many newer access points support up to 255 clients.