3Com OfficeConnect 3C840, User Manual

Page: 138 / 222

12-4 C
HAPTER
12: C
ONFIGURING
F
ILTERS
Creating generic filters can be a complex task. Only experienced users
should employ generic filters, and strictly in cases where data and
advertising filters cannot provide the filtering capabilities that you require.
Creating Filters
Overview
Filters can be set one of two ways in the OfficeConnect Remote 840:
■
Using Command Line Interface (CLI). (See Appendix D for
instructions to access the CLI.)
■
Using the OfficeConnect Remote 840 Manager.
The more flexible way of setting filters is through the Command Line
Interface (CLI). Both data and advertisement filters can be set using CLI.
For more information on accessing CLI, refer to the OfficeConnect
Remote 840 SDSL Router CLI User's Guide .
If you want to set up filters using the OfficeConnect Remote 840
Manager, go to the
“Step-by-Step Guide to Creating Filters Using the
OfficeConnect Remote 840 Manager” section.
Creating Filters
Using the
OfficeConnect
Remote 840
Manager
The OfficeConnect Remote 840 Manager supports data filters only (not
advertisement filters). Data filters are used to remove packets from the
normal flow of data traffic. They can be applied to IP, IPX, and/or Bridge
traffic.
Filters affect only those protocols which are currently active in the
OfficeConnect Remote 840.
Therefore, if the unit is set up to Bridge only, only bridge filters have an
effect on the data traffic; IP and IPX filters have no effect even if IP or IPX
traffic is being bridged. Internally (for greater efficiency), filters are
examined when a data packet is being processed by the protocol, not as
the packet enters or exits the unit (even though when filters are set up, it
looks like they take effect at the interface level). For example, when IPX
traffic is bridged, it is processed by the bridge protocol in the unit, not by
the IPX protocol. Therefore, a filter on IPX traffic would have to be a
bridge filter in this example.
There are two sets of criteria used in determining whether a filter affects
a packet.
840ug.book Page 4 Friday, July 7, 2000 2:23 PM