A Linux Firewall for Your Home
- Linux: The Choice of Network Engineers
- Is Your Home System at Risk?
- What's Safe?
- Is Your Home System a Server?
- Are Broadband Connections More Vulnerable?
- What Ports are Open?
- Using Netstat to List Ports
- Is Windows File Sharing a Risk?
- Using a Port Scan to Test Your System
- Checking for Windows NetBIOS Risks
- Definitions
Home users didn't use to worry if their computer systems were vulnerable to a hacker attack. And truth is, most dial-up connections are done from computers that are not vulnerable. Typical dial-up connections are dynamically assigned a new IP address each time the user connects. Since the connections are of a relatively short term—a few hours at most—and because the IP address always changes, it is rather difficult to crack through such a connection. Therefore, this kind of home dialup connection is generally safe.
Has that changed now with broadband 24-7 home connections through cable modems, Digital Subscriber Lines (DSL), and satellite systems? Are these connections more dangerous? Or is it just that the high speed of these connections makes the potential damage much more serious?
This guide will show you how to determine if your home system is safe. While connecting to the Internet can be a security risk if you are careless, there is no reason to get overly worried if you've set your system up correctly. Many home systems need the added security of a firewall, a device that sits between the home computer and the Internet connection and gives your home system a great deal of security.
If you need a firewall, the rest the guide will show you how to set one up using a computer running the Linux operating system.
Linux: The Choice of Network Engineers
Small and medium-sized businesses are choosing Linux firewalls as the best solution for their network security. A front-page report in PC Week magazine on February 21, 2000, highlighted this trend. PC Week is a magazine for IT professionals. The headline read, "IT abuzz over Linux-based routers."
Network engineers have found Linux firewalls effective and flexible. They are using Linux systems rather than the more expensive firewall routers sold by Cisco and others. Cisco and similar routers are used in complex business networks to handle a plethora of network services including SNTP, NAT, firewalls and so on. These capabilities can be remotely controlled and synchronized in a far-flung Wide Area Network that can span a wide geographical region. Usually these routers are maintained by certified Cisco engineers. A typical Linux firewall does not include all of the advanced network services featured in a Cisco router. The Linux firewall described in this guide is designed for strong security against attempts to crack into your home or small office system, but does not include the other advanced features found in Cisco routers.
And don't get me wrong—if you've got a budget like the Pentagon's and can afford the best, buy a Cisco firewall. It's great and will give you top-notch security.
However, if you have to fit a tight budget you can save thousands of dollars by using Linux firewall routers without sacrificing security. This is a particularly good choice for home users, who can take advantage of Linux and set up a strong firewall without spending a lot of money.
- < ahref="http://www.informit.com/content/index.asp?product_id={71E26116-2054-4821-890A-6A1B4B8876EF}&t={94AE5B48-1D7D-462A-A4A6-83CE19EC0705}">Part 2 of this article goes over what hardware you'll need to set up a Linux firewall router in your home.
- Part 3 covers the software you'll be using and how to make it work.