Many hardware firewall products such as SDProxy. Firewalls can also keep a log of traffic for auditing purposes. Types of firewalls Several types of firewalls exist and range in size from personal one-user versions to complete interprise systems designed to protect tens of thousands of computers. Most common however are as follows Personal windows based software. Each type of firewall has its' own pros and cons.
Personal firewalls are useful for single users, but become hard to manage in a multi-user network.
Larger systems typically cost more and require more skill to manage. Personal Firewalls Personal firewalls are usually Windows based software products that are designed to protect Windows computers from the Internet. The following are several products that are available from various vendors. Private Desktop Norton Internet Security 2000 SyShield ZoneAlarm 2.0 Software For Servers. Some firewalls can give you control over which computers on your LAN may have access, and wich may not.