User manual

Firewall
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6. Firewall
The CyberGuard SG appliance is equipped with a fully featured, stateful firewall. The
firewall allows you to control both incoming and outgoing access, so that PCs on the LAN
can have tailored Internet access facilities and are shielded from malicious attacks. By
default the firewall is active, and allows all outgoing connections and blocks all incoming
connections.
The CyberGuard SG appliance’s stateful firewall keeps track of outgoing connections
(e.g. a PC on your LAN requesting content from a server on the Internet) and only allows
corresponding incoming traffic (e.g. the server on the Internet sending the requested
content to the PC).
Sometimes it may be useful to allow some incoming connections, e.g. if you have a mail
or web server on your LAN that you want to be accessible from the Internet. These
situations are catered for by configuring Packet Filtering rules.
Generally, the majority of customizations to the default firewall ruleset will be done
through Packet Filtering, see the Packet Filtering section later in this chapter for details.
Incoming Access
The Incoming Access section allows you to control access to the CyberGuard SG
appliance itself, e.g. for remote administration. Click Incoming Access on the Firewall
menu to show the Incoming Access configuration page.