Changing The Route Loop Prevention Method - Foundry Networks Switch and Router Installation And Configuration Manual

Foundry Switch and Router Installation and Configuration Guide
• If a RIP neighbor filter is already configured and you are adding a new filter, click on the Add Neighbor
Filter link to display the RIP Neighbor Filter configuration panel, as shown in the following example.
• If you are modifying an existing RIP neighbor filter, click on the Modify button to the right of the row
describing the filter to display the RIP Neighbor Filter configuration panel, as shown in the following
example.
5. Enter the filter ID.
6. Select either Permit or Deny as the action.
7. Enter the IP address of the RIP neighbor router.
8. Click the Add button to save the change to the device's running-config file.
9. Select the Save link at the bottom of the dialog. Select Yes when prompted to save the configuration change
to the startup-config file on the device's flash memory.
To modify or delete a RIP neighbor filter:
1. Log on to the device using a valid user name and password for read-write access. The System configuration
dialog is displayed.
2. Click on the plus sign next to Configure in the tree view to expand the list of configuration options.
3. Click on the plus sign next to RIP in the tree view to expand the list of RIP option links.
4. Click on the Neighbor Filter link.
5. Click the Modify or Delete button next to the filter that is to be changed or deleted. If you click Modify, enter
the changes to the Action or IP Address fields and then click the Modify button apply the changes. If you click
Delete, the filter is removed immediately.
6. Click the Add button to save the change to the device's running-config file.
7. Select the Save link at the bottom of the dialog. Select Yes when prompted to save the configuration change
to the startup-config file on the device's flash memory.

Changing the Route Loop Prevention Method

RIP can use the following methods to prevent routing loops:
• Split horizon – The Layer 3 Switch does not advertise a route on the same interface as the one on which the
router learned the route. This is the default.
• Poison reverse – The Layer 3 Switch assigns a cost of 16 ("infinite" or "unreachable") to a route before
advertising it on the same interface as the one on which the router learned the route.
These loop prevention methods are configurable on an individual interface basis.
NOTE: These methods are in addition to RIP's maximum valid route cost of 15.
16 - 12 December 2000