Motorola 7000 用户手册

Netopia Embedded Software Version 7.7.4 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 display the Force Rout-

ing options.

•

Check the 

Force Route checkbox.

•

Enter the 

Gateway IP address in standard dotted-quad nota-

tion 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.

Netopia Embedded Software Version 7.7.4 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.

If you check the 

Idle Reset checkbox, a match on this rule will keep the WAN connection alive by resetting 

the idle-timeout status.

The Idle Reset setting is used to determine if a packet which matches the filter will cause an “instant-on” 
link to connect, if it is down; or reset its idle timer, if it is already up. For example, if you wanted ping traffic 
not to keep the link up, you would create a filter which for wards a ping, but with the Idle Reset checkbox 
unchecked.