Firewalls – Dedicated Proxy Servers

Dedicated proxy servers differ from application-proxy and circuit-level gateways in that while they retain proxy control of traffic, they do not have firewalling capabilities.

Although dedicated proxy servers are not firewalls, they are described in this section because of their close relationship to application-proxy gateway firewalls and circuit-level gateway firewalls. Many proxies are application-specific, and some actually perform analysis and [..]

IPv6

IPv6 is a new version of IP that is increasingly being deployed. Although IPv6’s internal format and address length differ from those of IPv4, many other features remain the same—and some of these are relevant to firewalls.

For the features that are the same between IPv4 and IPv6, firewalls should work the same. For example, blocking all inbound and outbound traffic that has not been expressly permitted by the firewall policy [..]

Firewalls and Network Architectures

Firewalls are used to separate networks with differing security requirements, such as the Internet and an internal network that houses servers with sensitive data. Organizations should use firewalls wherever their internal networks and systems interface with external networks and systems, and where security requirements vary among their internal networks. This section is intended to help organizations determine where firewalls should be placed, and where other networks and systems should be [..]