3Com OfficeConnect 3C100XF Cli User's Manual

Also see for OfficeConnect 3C100XF: Quick start guide

Contents

3Com OfficeConnect 3C100XF Cli User's Manual Manual pdf 215 page image

Creating Filters 27-5For example, a generic filter rule might look like this:010 ACCEPT generic => origin = data/offset = 22/length = 6/mask = 0xFFFFFFFFFFFFF/value = 0x0800096f39c8;Specifying the Filtering ActionYou can specify the filtering action for each protocol section that determineswhether a packet is accepted or rejected, if no match occurs with any of the rulesdefined in the section. To do this, enter one of the following values as the last ruleline of the section: permit denyFor example, the following entry would reject IP packets that did not match any ofthe rules defined in the IP protocol section:#filterIP:010 ACCEPT tcp-dst-port>=24;020 ACCEPT src-addr = 128.100.033.001;030 ACCEPT dst-addr = 200.135.038.009;040 DENY;If you do not specify a filtering action, the default filtering action is PERMIT.Creating Filter Files You can create filter files on your PC using any text editor. Once the file is created,you’ll use the Trivial File Transfer Protocol (TFTP) to place the filter file in FLASHmemory on your OfficeConnect Gateway.Table 27-3Field Descriptionline # Each rule must have a unique number (1-999). You Must ArrangeRules In Increasing Order.verb This field can be one of the following: ACCEPT - allow the packet access if the condition is met REJECT - do not allow the packet access if the condition is met AND - logically use the AND condition with condition of thenext rule to determine if the packet is accepted or rejected.Both defined conditions must be met.keyword The keywords for a generic filter is always GENERIC.operator The operator for a generic filter rule is always: =>origin Can be either FRAME or DATAoffset Number of bytes offset from the origin.length Number of bytes to compare and mask.mask Bit mask in hexadecimal format for logical and packet content.value The value in hexadecimal format used to compare with the maskedpacket contents