Define the term - Proxy servers

These types of firewalls have been further classified into two types: application level gateways and circuit level gateways.

The application level gateways establish a connection to a remote system on behalf of specific applications. This type of firewall is usually a collection of application proxies, with a one-to-one relationship between the application used and its proxy.

Whereas the circuit level gateways provide the proxy or relay capabilities in a much-generalised form, which is not limited to specific applications. The primary advantage of such firewalls over application level gateways is that they do not require a specific application proxy for each new application that needs to be communicated outside the internal network.

Although in terms of security measure the proxy servers are very secure, they require a lot of programming which can result in a delay in release of new proxies for application level gateways as well as tend to be highly CPU intensive, thereby directly having impact on the overall network performance.