Set Split-horizon Processing
Updated: April 30, 2010
Applies To: Windows Server 2008, Windows Server 2008 R2
Split horizon is a routing technique that helps prevent routing loops on IP networks. When split-horizon processing is enabled on a router interface, routes that are received through that interface from a neighboring router are not included in routing updates that are sent to the neighboring router through that interface. When split-horizon processing is disabled, routes learned through an interface are included in the routing updates that are sent through the same interface.
Split-horizon processing is enabled by default on all new RIP-enabled interfaces.
If you are using a spoke-and-hub Frame Relay topology, the Frame Relay interface for the hub router must have split-horizon processing disabled.
To enable split-horizon processing on a router interface
Membership in the local Administrators group, or equivalent, is the minimum required to complete this procedure.
Open the Routing and Remote Access MMC snap-in.
In the console tree, expand the router name, expand IPv4, and then select RIP.
In the details pane, right-click the interface on which you want to configure split-horizon processing, and then click Properties.
On the Advanced tab, either select the Enable split-horizon processing check box or clear the Enable split-horizon processing check box, and then click OK.