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VRF Instances

A routing instance is a collection of routing tables, interfaces, and routing protocol parameters. The interfaces belong to the routing tables, and the routing protocol parameters control the information in the routing tables. In the case of VPNs, each VPN has a VPN routing and forwarding (VRF) instance.

A VRF instance consists of one or more routing tables, a derived forwarding table, the interfaces that use the forwarding table, and the policies and routing protocols that determine what goes into the forwarding table. Because each instance is configured for a particular VPN, each VPN has separate tables, rules, and policies that control its operation.

A separate VRF table is created for each VPN that has a connection to a CE router. The VRF table is populated with routes received from directly connected CE sites associated with the VRF instance, and with routes received from other PE routers in the same VPN.

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