Firwall and VPN Services
Assets and threats to assets on the Internet are increasing at a staggering rate, so we must protect our networks from dangers both known and unknown. One popular tool for accomplishing this task is firewalls. These networking products have evolved a lot over the past several years. Simply blocking unwanted traffic and passing authorized traffic between networks isn't enough for today's firewalls. We expect more than just packet filtering. We want important security functions, such as Denial of Service (DoS) attack prevention and intrusion-detection systems.
Modern firewalls fall into one of two categories. Hardware-based firewalls (sometimes called appliances) use a particular hardware platform and a dedicated, proprietary OS. Software-based firewalls use standard hardware and a standard OS, such as Windows NT Server 4.0, that's been hardened (i.e., stripped of everything but the bare essentials in an effort to minimize security exposures). On top of the hardware and OS platform, both hardware-based and software-based firewalls run similar network-protecting firewall software.
Firewalls that offer a VPN component or option deserve special attention. Many companies deploy VPNs to secure communications between the corporate network and far-flung end users. Combining a VPN with a firewall in one solution makes administering the two functions easier.