Motorola 6161252-00-01 ユーザーズマニュアル
Security 10-37
TOS field matching
Motorola Netopia® Embedded Software Version 8.7.4 suppor ts two additional parameters in an IP filter: TOS
and TOS Mask. Both fields accept values in the range 0 – 255.
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.
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.
Example: You want packets with the TOS low latency bit to go through VC 2 (via gateway 127.0.0.3) instead of
your normal gateway. You would set up the filter as follows:
your normal gateway. You would set up the filter as follows:
Note:
Default Forwarding Filter
If you create one or more filters that have a matching action of for ward, then action on a packet matching none
of the filters is to block any traffic.
Therefore, if the behavior you want is to force the routing of a cer tain type of packet and pass all others through
the normal routing mechanism, you must configure one filter to match the first type of packet and apply Force
Routing. A subsequent filter is required to match and for ward all other packets.
Management IP traffic
If the Force Routing filter is applied to source IP addresses, it may inadver tently block communication with the
router itself. You can avoid this by preceding the Force Routing filter with a filter that matches the destination IP
address of the router itself.
If you create one or more filters that have a matching action of for ward, then action on a packet matching none
of the filters is to block any traffic.
Therefore, if the behavior you want is to force the routing of a cer tain type of packet and pass all others through
the normal routing mechanism, you must configure one filter to match the first type of packet and apply Force
Routing. A subsequent filter is required to match and for ward all other packets.
Management IP traffic
If the Force Routing filter is applied to source IP addresses, it may inadver tently block communication with the
router itself. You can avoid this by preceding the Force Routing filter with a filter that matches the destination IP
address of the router itself.
Add Input Filter
Enabled: Yes
Forward: Yes
Call Placement/Idle Reset: No Change
Force Routing: Yes
Gateway IP Address: 127.0.0.3
Enabled: Yes
Forward: Yes
Call Placement/Idle Reset: No Change
Force Routing: Yes
Gateway IP Address: 127.0.0.3
Source IP Address: 0.0.0.0
Source IP Address Mask: 0.0.0.0
Dest. IP Address: 0.0.0.0
Dest. IP Address Mask: 0.0.0.0
TOS: 16
TOS Mask: 16
Protocol Type: ANY
Source IP Address Mask: 0.0.0.0
Dest. IP Address: 0.0.0.0
Dest. IP Address Mask: 0.0.0.0
TOS: 16
TOS Mask: 16
Protocol Type: ANY
ADD THIS FILTER NOW CANCEL
Return/Enter to add this Filter to the Filter Set.
Enter the packet specific information for this filter.
Enter the packet specific information for this filter.