3Com 3C840 - Manual (Page 136)

12-2 C HAPTER 12: C ONFIGURING F ILTERS
Filtering
Capabilities The OfficeConnect Remote 840 provides an extensive set of data filtering
capabilities. The OfficeConnect Remote 840 supports the following
filtering capabilities:
■ Input and output data filtering.
■ Source and destination address filtering.
■
Protocol filtering.
■
Source and destination port filtering. A packet filter can control what
services local or remote users can access.
■
Route filtering can filter source and destination addresses in packets
that exchange routing table information.
■
Established session filtering. A packet filter can permit users to
connect with a remote network without letting remote users have
access to the local network (or vice versa).
Filter Classes The OfficeConnect Remote 840 supports three filter classes:
■
Input data — filter packets as they enter.
■ Output data — filter packets as they exit.
■ Embedded bypass — for periodic router protocol packets (IP RIP, IPX
RIP and IPX SAP)
Each filter class can be identified further by the following types:
Filter Types Filters can be classified by the following types:
■
Data filters — based on protocol-specific packet information.
■ Advertisement filters — based on broadcast packet information (IP
RIP, IPX RIP, and IPX SAP).
■
Generic filters — based on packet structure.
Data Filters Data filters control network access based on the protocol, source /
destination address, and port designation (e.g., TCP and UDP port
designations) of the packet. The following table describes the data filters
supported.
840ug.book Page 2 Friday, July 7, 2000 2:23 PM