Novell NETWARE 6-DOCUMENTATION Manual page 1876

IPX NetBIOS and Packet Forwarding Filters
TCP/IP Filtering
16
Filter Configuration
Incoming RIP filters
Incoming RIP filters let the router discard information about a particular
network. The filtered network is not recorded in the local forwarding
table and cannot be propagated to other routers, servers, or users. The
filter includes the network and the source of the route. The source
identifies the interface or interface group from which the routing
information was received. This is the most effective route filter for
improving security.
WARNING:
RIP filters work only on routers running the RIP protocol. They do not
work for routers running the NLSP protocol. Use RIP filters with care because they
can partition a physical network into two or more segments.
NetBIOS filters allow the router to forward NetBIOS broadcast packets only
on selected interfaces.
IPX packet forwarding filters allow the router to filter a packet based on the
source and destination interface fields, the packet type, and the source and
destination address type. The interface can be specified as an interface or
interface type, and address types can be specified as any address, network, or
node. Some services can be identified by the presence of expected values in
the Packet Type and/or Destination Socket fields.
NOTE:
IPX NetBIOS and packet forwarding filters work while using either NLSP or
RIP/SAP routing modes.
The TCP/IP protocol supports the following types of filters:
IP outgoing route filters
IP incoming route filters
Outgoing EGP filters
Incoming EGP filters
OSPF external route filters
Packet forwarding filters
For more information about TCP/IP filtering, refer to
"IP Routing Information Filters" on page 17
"IP Packet Forwarding Filters" on page 18