User Guide

Understanding 9
Filter Configuration
103-000178-001
August 29, 2001
Novell Confidential
Manual 99a38 July 17, 2001
1 Understanding
This chapter describes the Filter Configuration utility (FILTCFG) that you use
to configure filters that selectively discard packets to be sent or received by a
router. Filters let you control the service and route information that is accepted
or advertised by a router.
Filters can be useful when you want to limit specific kinds of traffic to certain
parts of your network topology, or when you want to provide a certain level
of security.
The Use of Filters
The Novell
®
Internet Access Server 4.1 routing software supports filtering to
control the service and route information that is accepted or advertised by a
router. Filters are useful when you want to limit specific types of traffic to
certain parts of your network and when you want to provide a certain level of
security. You use FILTCFG to configure the filters for the Internetwork
Packet Exchange
TM
(IPX
TM
) protocol, IP, AppleTalk*, and the source route
bridge to selectively discard packets sent or received by a router. The
following types of filters are supported:
 Packet forwarding —Prevents selected data packets from being
forwarded by the router. Packet forwarding filtering is available for IPX
and TCP/IP.
 Service information —Limits the services added to the service
information (SAP) tables of specified routers. Service information
filtering is available for IPX and AppleTalk.
 Routing information —Limits the routes added to the routing tables of
specified routers. Routing information (RIP) filtering is available for IPX,
AppleTalk, and TCP/IP.