There are lots of things that scare people about the Internet. Nigerian scammers, hackers, LOLCats. You know, the usual stuff.
While there is no perfect defense from any of those, especially the lolcats, implementing a firewall on your internet connection is a big step in the right direction.
A firewall is, in it’s most basic form, something that prevents network traffic from going to certain places. Think of it as a combination filtering and direction control system. Firewalls are available as software for a single computer, or as a combination hardware and software device for networks.
The most common firewall, at least for smaller companies, is a hardware based firewall that is built into your Internet router. It is generally setup to allow all traffic from the internal network (inside your company) out to the Internet, and block all traffic from the Internet that is trying to get into your companies network. It does this by watching where network traffic originates, makes a decision if it will allow that traffic to pass, and either lets it through or drops it. The firewall also keeps track of the traffic that it allows out, so that the return information can get back to the computer on the inside that requested it.
These firewalls also give you the ability to allow traffic from the Internet to come in to your network. Why would you want to do that? Well, if your email server is in your office, or you webserver is, then you’d need to tell the firewall to allow appropriate traffic from the Internet in to those servers. If you aren’t sure if you need to do that, or are sure you do, but don’t feel comfortable doing so, please contact a professional to do the work for you. It’s pretty straightforward, and shouldn’t take long at all in a small office setting.
Firewalls are also available as software for your computer. Both Windows and OS X have built in firewalls that can be used to allow traffic from your network to get to your computer, or can be used to stop your computer from communicating with the network.
There are also 3rd Party software packages from companies like McAffee or Symantec that you can install on your computer. Be aware of the issues that can come up if install one of these pacakages on your computer and it’s also running the native Windows firewall – lots of very weird issues can come from having both of them active at the same time.
A firewall won’t protect you from bad decisions made online, like sending your bank account info to Nigeria, or browsing LOL Cats, but it will definitely help to prevent unauthorized access into your network from the Internet. And given how secure even very small, low cost firewalls can be, there is no reason that you shouldn’t have one between your systems and the Internet.