Router/Firewall

I’m approaching this subject from the standpoint of home and small office users. A router/firewall is really a residential (home) gateway. Just as the term applies, a gateway is a way to get in and out of a place. Throughout this post, I’m going to use the term router and firewall as if they meant the same thing. They really are not the same, but for home users, the concept or purpose is the same.

A firewall's basic task is to regulate some of the flow of traffic between computer networks of different trust levels. Typical examples are the Internet which is a network with no trust and an internal network which is a network of higher trust.

A residential gateway (or router/firewall), is a hardware device connecting a home network with a wide area network (WAN) or the Internet. The residential gateway provides port translation (NAT), allowing all the computers in a small network to share one IP address and Internet connection. The residential gateway may sit between the modem and the internal network, or a DSL or cable modem may be integrated into the residential gateway.

The function of a router is that it “hides” the information (data) on your internal network (your home computers) from people outside of your network. What does that mean? It means that it protects your personal information from anyone outside your home from accessing it. It’s like a data traffic cop.

In today’s “environment” where identity theft runs high, I recommend that no one connect a computer to the internet without a router/firewall in operation.

There are two types of firewalls. There is an “appliance” (piece of equipment) firewall and there is a software firewall. An appliance firewall would be a piece of equipment that you would purchase, such as a Linksys router (see my post on Wireless networking tips). A software firewall is a piece of software that you install on your computer; a good free software firewall is ZoneAlarm. Both act like a traffic cop and only let in and out what is OK. You can install both an appliance firewall and a software firewall. I do not recommend a software firewall alone.