Arris NVG595, Руководство администратора

Страница: 60 / 226

Administrator’s Handbook
60
Link: Packet Filter
When you click the
Packet Packet Packet Packet
Filter link the
Packet Filter
screen opens.
Security should be a high priority for anyone administering a network connected to the Internet. Using packet
filters 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.
ARRIS’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
WARNING :
Before attempting to configure filters and filtersets, please read and understand this entire section thor-
oughly. The ARRIS Gateway incorporating NAT has advanced security features built in. Improperly adding fil-
ters 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 likelihood of
implementation errors.
• Enabling a large number of filters can have a negative impact on performance. Processing of packets 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. Filtersets are
not a substitute for password protection, effective safeguarding of passwords, and general awareness of how
your network may be vulnerable.