Security appliance

A security appliance is any form of server appliance that is designed to protect computer networks from unwanted traffic.^[1]

Types of security appliances

Active devices block unwanted traffic. Examples of such devices are firewalls, anti virus scanning devices, and content filtering devices.

Passive devices detect and report on unwanted traffic, such as intrusion detection appliances.

Preventative devices scan networks and identify potential security problems (such as penetration testing and vulnerability assessment appliances).

Unified Threat Management (UTM) appliances combine features together into one system, such as some firewalls, content filtering, web caching etc.

Examples of a security appliance include:

ApplianSys AUDITbox vulnerability assessment and CACHEbox web cache/content filtering appliances.
Blue Coat Systems ProxySG UTM appliance.
CISCO Systems PIX firewall and Cyberoam UTM appliances.
Check Point UTM-1 Edge, Power-1, VSX-1, IP Appliances (Formerly a Nokia Product Line).^[2]
eEye Security Management Appliance 1505 for vulnerability assessment and endpoint protection.
Finjan Vital Security - Secure Web Gateways.^[3]
F5 Networks BIG-IP security appliances.
Global Technology Associates, Inc. Firewall Appliance
IronPort Web and Email security appliances.
Mirapoint Email security appliance.
SonicWall UTM appliances.
Rapid7
Radware DefensePro - Application Security & Network Intrusion Prevention System. ^[4]