Fortunately, there are readily-available solutions that can be used to improve site security. A firewall system is one technique that has proven highly effective for improving the overall level of site security. A firewall system is a collection of systems, routers, and policy placed at a site's central connection to a network. A firewall forces all network connections to pass through the gateway where they can be examined and evaluated, and provides other services such as advanced authentication measures to replace simple passwords. The firewall may then restrict access to or from selected systems, or block certain TCP/IP services, or provide other security features. A well-configured firewall system can act also as an organization's ``public-relations vehicle'' and can help to present a favorable image of the organization to other Internet users.
A simple network usage policy that can be implemented by a firewall system is to provide access from internal to external systems, but little or no access from external to internal systems. However, a firewall does not negate the need for stronger system security. There are many tools available for system administrators to enhance system security and provide additional logging capability. Such tools can check for strong passwords, log connection information, detect changes in system files, and provide other features that will help administrators detect signs of intruders and break-ins.