3Com OfficeConnect Remote 812 manual Overview, Creating Filters Using, Command Line, Interface

6-48CHAPTER 6: MANUAL SETUP

IPX-SAP	Controls the content of Service Advertising Protocol (SAP) packets that are sent
	out or received on specific ports. The IPX-SAP filter rules allow filtering on service
	type, server name, network address, node address, and socket number fields of
	the service entry. The forwarding process uses the filter information to prevent
	the service information from being included in the SAP packet.
IPX-RIP	Controls the content IPX RIP packets that are sent out or received on specific
	ports. The IPX RIP filtering process filters addresses from the RIP packet upon
	transmission, and does not enter routes into the routing table upon receipt.

Generic Filters	Generic filters are protocol-independent and are specified by byte and offset
	values in a packet. Packets are filtered by comparing each packet’s offset value and
	byte information with the values that you define in the filter. The router will accept
	or reject the packet based on the result.
	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	Filters can be set using either the CLI or the OCR 812 Manager.
Overview	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, see Chapter 1, Establishing Communications with
	the OfficeConnect Remote 812.
	Data Filters can be set using the HTML Manager (the OCR 812 Manager). 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. Advertisement filters are used to restrict
	information in outgoing or incoming advertisement packets, i.e. IP RIP, IPX RIP, and
	IPX SAP packets.
Creating Filters Using	Before creating a filter file, you should carefully identify the information you want
Command Line	to filter. Decide if you want a filter that discards packets (such as reject all IP
Interface	packets whose IP source address is 192.168.200.50) or accept only a subset of
	packets (such as accept only bridged packets if the destination MAC address is
	002069000001 or 002069000002). Also determine where you want to place the
	filter. For example, figure out if you want to apply the filter to packets coming into
	the Ethernet port, to packets going out the WAN (ATM) port, or to packets coming
	from a specific VC/remote site.
	The first step in creating a filter on the OCR 812 is to create a file using a text
	editor on a workstation. The file will contain filters defined in the OCR 812 filter
	syntax (described below). File names should be short and descriptive, such as IP.FLT.
	The next step is to use TFTP (Trivial File Transfer Protocol) to copy the filter file from
	the workstation to the OCR 812.
	You then use CLI commands to add the filter file to the list of filters and apply the
	filter to the appropriate interface or VC / remote site profile.