- A guide to securing your home computer system with a Linux firewall
- 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
Definitions
Broadband telecommunications refer to a single high-speed line that carries multiple channels of data. Cable modems, for example, use a coaxial or fiberoptic cable to carry multi-channel transmissions. Regular telephone service, by contrast, uses baseband transmission, which allows only one channel of data at a time.
A firewall server is a router that sits between your computer or a computer network and a larger-scale network such as the Internet. Firewall servers provide increased security by preventing outsiders from accessing your private data while you are connected to the Internet. The two most common types of firewall server are packet filtering firewalls and proxy firewalls. Packet filters look at each packet entering or leaving the network and accepts or rejects it based on user-defined rules. Proxy firewalls intercept connections coming in or going out through one port and use a set of rules to either forwarding them via another port or reject the connection.