A very important part of securing your system is the firewall. A firewall, when properly designed and setup, will allow you complete access from inside your of your local network to outside of your local network, in other words Internet access, but prevent unauthorized access into your network from the outside.
There are a wide array of firewall products available. These can be software based, running on each computer. They can be hardware based, where all traffic to and from the outside is routed through a separate device. Or, they can be a combination of both of these.
As every company will differ in their need for a firewall, there is no one solution that is best for everyone. A company with remote sites, may need to communicate with the corporate site only. Each site may need to communicate with all other sites. In both of these cases, the needs are different than a single location, that needs Internet access, and to block any unauthorized outside access.
We have extensive experience with a variety of firewall configurations. We can help you with the best design to fit your company and any specific needs that you have.