Packet Filter - Motorola nvg589 Administrator's Hanbook

Link: Packet Filter

Packet Filter

When you click the
Security should be a high priority for anyone administering a network connected to the Internet. Using packet fil-
ters to control network communications can greatly improve your network's security. The Packet Filter engine
allows creation of a maximum of eight Filtersets. Each Filterset can have up to eight rules configured.
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WARNING:
Before attempting to configure filters and filtersets, please read and understand this entire section
thoroughly. The Motorola Gateway incorporating NAT has advanced security features built in.
Improperly adding filters and filtersets increases the possibility of loss of communication with the
Gateway and the Internet. Never attempt to configure filters unless you are local to the Gateway.
Although using filtersets can enhance network security, there are disadvantages:
• Filters are complex. Combining them in filtersets introduces subtle interactions, increasing the like-
lihood of implementation errors.
• Enabling a large number of filters can have a negative impact on performance. Processing of pack-
ets will take longer if they have to go through many checkpoints in addition to NAT.
• Too much reliance on packet filters can cause too little reliance on other security methods. Filter-
sets are not a substitute for password protection, effective safeguarding of passwords, and general
awareness of how your network may be vulnerable.
Motorola's packet filters are designed to provide security for the Internet connections made to and from your net-
work. You can customize the Gateway's filtersets for a variety of packet filtering applications. Typically, you use fil-
ters to selectively admit or refuse TCP/IP connections from certain remote networks and specific hosts. You will
also use filters to screen particular types of connections. This is commonly called firewalling your network.
Before creating filtersets, you should read the next few sections to learn more about how these powerful security
tools work.
link the Packet Filter screen appears.
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