Tools to limit your network’s exposure

If you have a small home network and a device such as a wireless router providing connectivity to all the computers on the network, what can you do to protect the network from the outside?

First and foremost, enable NAT (Network Address Translation) support for your Internet gateway. Most routers (wired and wireless) have NAT capability. NAT separates your local network from the Internet by creating an isolated group comprising the computers in your local subnet.

Secondly, you should configure client firewalls to allow sharing for your local network only; this will block incoming connections and automated probes from the Internet.

You may want to test your settings by using an independent third-party tool or service that tells you whether any computers on your network are vulnerable (have ports open to the Internet). One test we recommend is from the respected security expert Steve Gibson; it is designed to show the effectiveness of your clients’ ports isolation. The test is called ShieldsUP! and it is available here.