Netopia 2200 - Manual (Page 173)

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Policy-based Routing using Filtersets
Policy-based Routing using Filtersets
Netopia Firmware Version 7.6 offers the ability to route IP packets using criteria other than
the destination IP address. This is called policy-based routing.
You specify the routing criteria and routing information by using IP filtersets to determine
the for warding action of a par ticular filter.
You specify a gateway IP address, and each packet matching the filter is routed according
to that gateway address, rather than by means of the global routing table.
In addition, the classifier list in a filter includes the TOS field. This allows you to filter on
TOS field settings in the IP packet, if you want.
To use the policy-based routing feature, you
create a filter that for wards the traffic.
• Check the Forward checkbox. This will dis-
play the Force Routing options.
• Check the Force Route checkbox.
• Enter the Gateway IP address in standard
dotted-quad notation to which the traffic should
be for warded.
• You can enter Source and Destination IP
Address(es) and Mask(s), Protocol Type,
and
Source and Destination Port ID(s) for the
filter, if desired.
TOS field matching
Netopia Firmware Version 7.6 includes two
parameters for an IP filter:
TOS and TOS
Mask. Both fields accept values in the range 0
– 255.
Cer tain types of IP packets, such as voice or
multimedia packets, are sensitive to latency
introduced by the network. A delay-sensitive
packet is one that has the low-latency bit set in
the TOS field of the IP header. This means that if such packets are not received rapidly, the
quality of ser vice degrades. If you expect to route significant amounts of such traffic you
can configure your router to route this type of traffic to a gateway other than your normal
gateway using this feature.
The TOS field matching check is consistent with source and destination address matching.