by Scott Kubinski

A couple of months ago I said that you should install a Router/Firewall to protect your small business network.  So what are a router and a firewall?  Do you need both?

A firewall filters and/or blocks incoming and outgoing internet data according to a set of rules.  A router on the other hand, routes data and allows multiple PC’s on a LAN (Local Area Network) to share a single internet connection.  How?  A public internet IP address, used to route data to you, is assigned to the router instead of a computer. Each device on your network has a unique local IP address, making it possible for the router to direct data from the internet to a specific computer.  A NAT (Network Address Translation) router allows connections in only one direction: from your network out to the internet.  Connections INITIATED from the internet towards your network cannot get through NAT.  Consequently, a NAT router, while not a true firewall, functions as a simple hardware firewall.

NAT routers are provided by most broadband Internet Service Providers when you establish the internet connection.  In my opinion: if you have only one physical business location and you can trust all the computers on your LAN, a NAT router provides 99.9999% of what you need in a firewall. Blocking external threats is by far the single most important role of a firewall these days.

Now, before you call me and argue you must have an outbound firewall in case malware is connecting to the internet, consider this; if an outbound firewall detects something that is malicious in nature it's because your machine is ALREADY infected. Your inbound defense has failed and your network is compromised!

If your network has more than one computer, you need a router.  If your network is attached to the internet, you ABSOLUTELY need a firewall.  The good news is:  If you connect to the internet via a broadband connection, you likely already have both.

Mr. Scott Kubinski has been an I.T. Consultant for over 25 years and has been with New Horizon I.T. Consulting, Inc. for the last three years.  Scott can be reached for comment or questions at his office (951) 602-7699 or via email at This e-mail address is being protected from spambots. You need JavaScript enabled to view it .