Packet Filtering Vs Firewall; Packet Filtering; Figure 14-5 Big Picture - Filtering, Firewall And Nat - ZyXEL Communications ZyXEL ZYWALL10 User Manual

ZyWALL 10 Internet Security Gateway

14.3 Packet Filtering Vs Firewall

Below are some comparisons between the ZyWALL's filtering and firewall functions.

14.3.1 Packet Filtering:

!
The router filters packets as they pass through the router's interface according to the filter rules you
designed.
!
Packet filtering is a powerful tool, yet can be complex to configure and maintain, especially if you need
a chain of rules to filter a service.
!
Packet filtering only checks the header portion of an IP packet.
14-6
Figure 14-5 Big Picture — Filtering, Firewall and NAT
Introducing the ZyWALL Firewall