3Com HomeConnect 3CP3647 Cli User's Manual

Also see for HomeConnect 3CP3647: Installation guide

Contents

4-4 CHAPTER 4: FILTERING CAPABILITIESThe OR operation can be implemented by successive rules. For example, to accepta packet if the source address is xxx, or the destination address is yyy, thefollowing rules are used:BR-ETH:1 ACCEPT src-addr=00-20-69-00-00-01;2 ACCEPT dst-addr=00-20-69-00-00-02;999 DENY;The following table describes the keywords for the bridge protocol section andtheir legal operators used in the rule syntax. (xx is a hex number).Generic Filter Rule The syntax for generic filters is slightly different than that for other protocol filters: #> GENERIC => ORIGIN = FRAME/OFFSET = <# of bytes>/LENGTH = <# of bytes>/MASK = < 0x Mask>/VALUE = <0x value>n ORIGIN - The location in the packet to start the offset count. This is at byte 0(FRAME).n OFFSET - The number of bytes from the origin to skip before comparing thevalue to the packet contents.n LENGTH - The number of bytes in the packet to compare to the value.n MASK - The mask to logically "and" with the packet contents beforecomparing with the value (hex).n VALUE - The value (hex) to compare to the packet contents.For example, a generic bridge filter to prevent all IP packets from being bridged is:BR-ETH:1 rejectgeneric=>origin=frame/offset=12/length=2/mask=0xFFFF/value=0x0800;Step by Step Guide toCreating Filter FilesThis section presents a step-by-step guide for creating and applying filters. Thesesteps assume that the filter file is created on a remote workstation and thentransferred to FLASH memory using TFTP. If you use the CLI create text commandto create the filter file, you can omit steps 9 and 10.To create a filter file:1 Open a new text file. Enter the file descriptor on the first line: #filter2 Enter the section header followed by a colon for the protocol rules you want todefine. For example: BR-ETH:3 You can comment a section header out by placing a # sign before the sectionheader. This is useful if you want to insert a placeholder for a protocol section youTable 4-2 Protocol KeywordsProtocolSection Keyword Operators Description and Value RangeBR-ETH src-addrdst-addrgeneric=, !==, !==Source MAC address (xx-xx-xx-xx-xx-xx)Destination MAC address (xx-xx-xx-xx-xx-xx)Generic filter