Chapter 4 Firewall Protection and Content Filtering
The ProSafe VPN Firewall 50 provides you with Web content filtering options such as Block Sites and Keyword Blocking. Parents and network administrators can establish restricted access policies based on
About Firewall Security
A firewall is a special category of router that protects one network (the “trusted” network, such as your LAN) from another (the untrusted network, such as the Internet), while allowing communication between the two.
A firewall incorporates the functions of a NAT (Network Address Translation) router, while adding features for dealing with a hacker intrusion or attack, and for controlling the types of traffic that can flow between the two networks. Unlike simple Internet sharing NAT routers, a firewall uses a process called stateful packet inspection to protect your network from attacks and intrusions. NAT performs a very limited stateful inspection in that it considers whether the incoming packet is in response to an outgoing request, but true Stateful Packet Inspection goes far beyond NAT.
Using Rules to Block or Allow Specific Kinds of Traffic
Firewall rules are used to block or allow specific traffic passing through from one side to the other. You can configure up to 600 rules on the FVS338. Inbound rules (WAN to LAN) restrict access by outsiders to private resources, selectively allowing only specific outside users to access specific resources. Outbound rules (LAN to WAN) determine what outside resources local users can have access to.
A firewall has two default rules, one for inbound traffic and one for outbound. The default rules of the FVS338 are:
•Inbound: Block all access from outside except responses to requests from the LAN side.
Firewall Protection and Content Filtering |
