Chapter 11 - TCP/IP Filtering | 187 |
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IP Route Filter Rule Options
A direction can optionally be specified with in, out or both. If no direction is specified, both is assumed.
•Filter rules specifying in are only applied to routing packets coming into the device.
•Filter rules specifying out are only applied to routing packets being sent from the device.
•Filter rules specifying both are applied to routing packets in both direc- tions.
IP Route Filter Rule Modifiers
Filter rules can be modified with the following parameters. When used, the modifiers must be put in a filter rule in the order shown below. By default, a filter rule is applied to all routing data.
•via <protocol(s)> This modifier specifies that the filtering rule should only be applied to routing data being received or transmitted by the designated routing protocol. Allowed values are icmp, rip, and ripv2. Multiple protocols may be listed, each separated by white space. The icmp keyword implies redirected routes.
•origin <protocol(s)> This modifier limits output rules to routes origi- nating from the designated protocol. Allowed values are icmp, rip, ripv2, static, and direct. Multiple protocols may be listed, each sepa- rated by white space.
•metricin <increment value> This modifier tells the device to increment the metric on incoming routes which match the filter rule. The metric is the number of routers on a route. By increasing or decreasing the metric, a particular route can be made more or less attractive. The value to incre- ment by can be from 1 to 15.
•metricout <increment value> This modifier tells the device to increment the metric on outgoing routes which match the filter rule. The metric is the number of routers on a route. By increasing or decreasing the metric, a particular route can be made more or less attractive. The value to incre- ment by can be from 1 to 15.
•from <IP address> or from <interface> This modifier tells the device to apply the rule only to routes coming from a specified IP address (where the address is in the same format as discussed above), or interface (e.g. Ethernet 0, WAN 1, etc.).
•to <IP address> or to <interface> This modifier tells the device to apply the rule only to routes being sent to a specified IP address (where the address is in the same format as discussed above), or interface (e.g. Ethernet 0, WAN 1, etc.).
