This article describes How to influence default best path determination mechanism by changing Local Preference.

 

Prerequisites

  1. Versa Headend should be deployed and functional
  2. Versa FlexVNF should receive same routes from two different next hops routers/devices

 

Here the route learnt from the Internet-Transport-VR is having the higher priority (Default priority 100) than MPLS-Transport-VR (priority 90)

 

 

 

Below, the output for 0.0.0.0/0 shows we are receiving route from both Internet-Transport-VR and MPLS-Transport-VR but Versa FlexVNF will install only one default route with higher Local Preference .

 

 

Below output of routing table shows only one default route installed that is from Internet-Transport-VR.

 

 

 

Configuration

  1. To change the Local preference on MPLS-Transport-VR higher then Internet-Transport-VR
  2. Select the appliance where you want to change the Local Preference.
  3. In the Appliance view, go to Configuration > Networking > Virtual Routers.
    Select the LAN-VR where you want to change the configuration.
  4. Click BGP on the left panel of the Configure Virtual Router screen and select the Instance ID.

 

 

  1. Select the BGP Instance and exact Peer/Group Policy to change the Local Preference.
  2. Click the Peer/Group Policy tab on the Edit BGP Instance screen, here we are changing the MPLS-Transport-VR Local Preference higher then Internet-Transport-VR.

 

 

  1. Select the Terms section and enter the match criteria of the route to be manipulated.
  2. We are changing the Local preference from 99 to 150 in MPLS-Transport-VR, so MPLS-Transport-VR default route will be installed in LAN-VR routing table.

 

 

Validation

  1. We can verify the configuration in CLI as below.

 

 

  1. We are receiving the default route from both, but higher Local Preference in MPLS-Transport-VR(150) then Internet-Transport-VR(100).

 

 

  1. Default route in routing table is changed from MPLS-Transport-VR to Internet-Transport-VR.


 

Troubleshooting

We can check the detail parameters on received routes and verify Local preference is correct or not.