I was involved in a provocative networking discussion recently, and it has some notable cyber security implications. One person asked, “Do I need a router, if I want to connect my PC to the internet, if I don’t want to use Wi-Fi?”
The answer, of course, is “no.” One could directly connect a PC to the Internet. I suppose many are. Even if those PCs are running some fantastic anti-virus and personal firewall, I still wouldn’t recommend it. Yes, I use a personal firewall product on each of the computers in my office and at home. But, I don’t fully trust any such product to be 100% safe. Plus, that personal firewall is a single layer of protection and participants in Learning Tree’s System and Network Security Introduction will know that I am strongly in favor of defense-in-depth.
That is, I want multiple layers of protection for my network. That way, if one is compromised, the other can still offer protection. If you go to any secure facility, there may be a guard gate, a front guard, and locked doors. All of these are layers of defense are designed to backstop or reinforce the prior layers. That Wi-Fi router provides an extra layer for my network.
I don’t know of any home or SOHO wireless routers without some level of firewall protection. The ones we were discussing, when the question came up surely have it. As long as that firewall is not disabled, it provides a layer of protection. But the router also provides some protection by the nature of its Network Address Translation(NAT) function.
NAT or Network Address Translation, is the feature that allows a single public IP address to serve multiple computers behind a router. It translates addresses of hosts “behind” the router to the router’s public address (and back again), so all the traffic from internal hosts appears – as far as the Internet is concerned – to come from the router. Part of the way this works, is that incoming traffic has to be matched to outgoing traffic. That means that arbitrary incoming traffic is blocked. So, when an attacker initiates an attack on my network, the router blocks the traffic.
The NAT and firewall protections are necessary, but one still has to run anti-virus and personal firewall software on each of the PCs to get the second layer of safety. It is also important to note that attackers can and do attack routers on the Internet. It is, therefore, essential to update the router software as necessary, if the manufacturer does not do it automatically.
So, please, if you are not using a firewall on your internet connection, do so. These devices are inexpensive, and if you want to disable the wireless feature, it is usually no more than a couple of mouse clicks to do so. Even if you don’t want to turn off WiFi ensure that you change the router’s default password to a strong one, so attackers can’t break in and turn off the firewall. If you are using the wireless feature, set a good, strong password for that too.
To your safe computing,