Predefining Gateways for Path Calculation

Consider predefining IP/gateway fix-up rules when you meet one of the following scenarios with gateway selections during a path calculation:

Gateway (interface) not found

Gateway of a device not correct

Specify gateways for all end systems in batch. For example, specify a gateway for all IPs in a network segment.

With the predefined Path IP and Gateway Fix-up Rules, when you input the source and destination to calculate a path, the system looks up the predefined gateways by matching both source and destination with that predefined in the fix-up rules.  

User Flow

The following use flow is recommended for fixing up Path IP and Gateways:

1.Define path gateway/IP fix-up rules.

2.Calculate a path.

3.View path results with fix-up rules applied.

Defining Path IP/Gateway Fix-Up Rules

1.Log in to the Domain Management page.

2.Select Operations > Advanced Tools > Path IP and Gateway Fix-up from the quick access toolbar.

3.Click Add. The sample below shows the gateway fix-up rule for a subnet.

4.Specify the original destination and source that you want to replace or assign gateways.

Tip: "*" indicates matching any IP.

Note: The operator between Source and Destination is AND. If you enter an exact IP address like "192.168.1.1" as the source and "*" as the destination, the system only matches the source without considering the destination input when selecting gateways in a path calculation.

4.Specify the IP replacements or gateways, respectively for the source and destination.

Note: At least one replacement is required, and others can be left blank.

5.Click OK to save the entry.

Viewing Matched Path IP and Gateway Fix-up Rules

When you start a path calculation, the system will check if the destination and source match any fix-up rules. If yes, the system will use the fix-up gateway or IP replacements (if defined in the fix-up rule) to calculate the path.

For example, calculate a path from 172.24.32.109 to 172.24.32.10. The source IP is in the range of the subnet (172.24.32.0/24) defined in the above fix-up rule. Therefore, the fix-up rule will apply to the path calculation as follows:

The gateway fix-up rule is enabled by default. To disable it, go to Path Settings before calculating a path.