[Contents] [Prev] [Next] [Index] [Report an Error]

## Overview of Firewall Services in Enterprise Manager Portal

The basic firewall that you configure will be enforced on all Internet access links subordinate to the subscriber you select in the navigation pane. When you have configured a basic firewall, you can create firewall exceptions—variances from the basic firewall—for specific categories of traffic.

Firewall exception rules block traffic that otherwise would be permitted to traverse the firewall, or to admit traffic that would otherwise be blocked. Exceptions specify criteria against which each packet is inspected.

How you configure firewall exceptions depends on which type of firewall service the ISP enabled. Enterprise Manager Portal can support one of the following:

- Stateless firewalls—Inspect each packet in isolation; they do not evaluate the traffic flow.

  With stateless firewalls, you can configure exceptions to take customized actions, such as policing specified traffic at a specified rate, or setting the ToS byte. By using customized actions, you can allow traffic from a specified IP address or for a specified IP protocol to traverse the firewall. In addition, you can specify quality of service (QoS) properties such as values for the type of service (ToS) byte.

- Stateful firewalls—Track traffic flows and conversations between applications and evaluate this information when applying exception rules.

  An application is typically associated with a stateful firewall rule. After a flow or conversation meets firewall criteria, packets in that flow can pass through the firewall. For example for an FTP connection, when an FTP control connection requests a file download, the stateful firewall knows to expect and allows a TCP data connection to start. You can also create firewall exceptions for traffic associated with a particular application protocol, such as FTP, that originates at a particular address in the enterprise.

[Contents] [Prev] [Next] [Index] [Report an Error]