Virtual Routing and Forwarding (VRF) in BGP/MPLS L3VPN enables multiple isolated routing tables within a single physical router, ensuring secure and independent routing for different customers. VRF instances maintain routing and forwarding information by importing routes from connected Customer Edge (CE) devices and remote VPN sites via MP-BGP PE routers. Each VRF can run its own routing protocols, such as OSPF, IS-IS, or E-BGP, enhancing isolation.

To optimize routing resources, a maximum route limit can be configured per VRF. This provides ability to control the number of imported dynamic routes that appear in the forwarding information base (FIB). When this limit is reached, new dynamic routes remain pending, while static and connected routes continue contributing to the total count. A threshold-based NetConf notification and syslog warning message can notify administrators when the route count approaches the limit, ensuring efficient resource management and maintaining network stability.

This feature enhances BGP/MPLS L3VPN scalability by allowing per-VRF route limits, ensuring independent routing tables for each VPN instance. It applies limits only to dynamic routes while accounting for static and connected routes in the total count. A threshold-based NetConf notification and syslog warning message notifies administrators when the route count nears the limit and clears once it drops below, ensuring efficient resource management.

Configure the maximum number of VRF FIB routes on a networking device.

This topology represents a basic MPLS Layer 3 VPN (L3VPN) setup using VRF instances and IS-IS as the Interior Gateway Protocol (IGP). The topology consists of two Customer Edge (CE) routers, CE1 and CE2, connected to a single Provider Edge (PE1) router via different virtual routing instances. CE1 is connected to PE1 through interface xe13.3, which is associated with VRF3, while CE2 connects via xe1.3, mapped to VRF3

The following configuration on the PE1 router defines a VRF instance (VRF3) with a maximum limit of 10 dynamic IPv4 FIB routes, applying a stop-install policy when the limit is reached and setting an 70% threshold for early warnings. It also configures interface xe13.3 with VLAN encapsulation and an IP address, ensuring proper traffic segmentation and routing within the VRF. Follow the steps below to configure the maximum number of VRF FIB routes on a networking device.

The running configuration on PE1 sets VRF3 with a 10-route FIB limit, an 80% threshold warning, and assigns VLAN encapsulation and an IP to interface xe13.3.

Validation ensures that the Max VRF FIB Routes Implementation functions as expected by verifying route limits, isolation, and NetConf notification and syslog warning message, preventing resource exhaustion and ensuring efficient routing operations.

The running configuration on P.

Validation ensures that the Max VRF FIB Routes Implementation functions as expected by verifying route limits, isolation, and NetConf notification and syslog warning message, preventing resource exhaustion and ensuring efficient routing operations.

The running configuration on PE2 sets VRF3 with a 10-route FIB limit, an 70% threshold warning, and assigns VLAN encapsulation and an IP to interface xe13.3.

Validation ensures that the Max VRF FIB Routes Implementation functions as expected by verifying route limits, isolation, and NetConf notification and syslog warning message, preventing resource exhaustion and ensuring efficient routing operations.

Use this command to set a limit on the number of dynamic routes installed in a VRF FIB, excluding static and connected routes.

Use the no form of the command without threshold keyword to disable maximum routes limit for a VRF.

Maximum FIB routes limit is disabled

Configuration mode

Introduced in OcNOS version 6.6.1.

Use this command to set a route limit in a VRF FIB and optionally configure a threshold percentage using the threshold keyword.

Use the no form of the command with threshold keyword to remove configured threshold percentage for the route limit.

Threshold limit is 80%.

Configuration mode

Introduced in OcNOS version 6.6.1.

 

The following provides definitions for key terms or abbreviations and their meanings used throughout this document: