© 2006 Cisco Systems, Inc. All rights reserved. MPLS v2.2—5-1 MPLS VPN Implementation Configuring VRF Tables

© 2006 Cisco Systems, Inc. All rights reserved. MPLS v2.2—5-2 Outline Overview What Are the VRF Configuration Tasks? Creating VRF Tables and Assigning RDs Specifying Export and Import RTs Using VPN IDs Assigning an Interface to a VRF Table Typical Configuration to Enable VRFs Summary

© 2006 Cisco Systems, Inc. All rights reserved. MPLS v2.2—5-3 VRF Configuration Tasks VRF configuration tasks: Create a VRF table Assign RD to the VRF Specify export and import route targets (Optional) Configure a VPN ID Assign interfaces to VRFs

© 2006 Cisco Systems, Inc. All rights reserved. MPLS v2.2—5-4 ip vrf name Router(config)# This command creates a new VRF or enters configuration of an existing VRF. VRF names are case-sensitive. VRF is not operational unless you configure RD. VRF names have only local significance. rd route-distinguisher Router(config-vrf)# This command assigns a route distinguisher to a VRF. You can use ASN:nn or A.B.C.D:nn format for RD. Each VRF in a PE router has to have a unique RD. Creating VRF Tables and Assigning RDs

© 2006 Cisco Systems, Inc. All rights reserved. MPLS v2.2—5-5 route-target export RT Router(config-vrf)# Specifies an RT to be attached to every route exported from this VRF to Multiprotocol Border Gateway Protocol Allows specification of many export RTs—all to be attached to every exported route route-target import RT Router(config-vrf)# Specifies an RT to be used as an import filter (Only routes matching the RT are imported into the VRF.) Allows specification of many import RTs (any route where at least one RT attached to the route matches any import RT is imported into the VRF.) Because of implementation issues, at least one export route target must also be an import route target of the same VRF in Cisco IOS Release 12.4(T) and earlier. Specifying Export and Import RTs

© 2006 Cisco Systems, Inc. All rights reserved. MPLS v2.2—5-6 route-target both RT Router(config-vrf)# In cases where the export RT matches the import RT, use this form of the route-target command. Sample router configuration for simple customer VPN: Specifying Export and Import RTs (Cont.) ip vrf Customer_ABC rd 65173:15 route-target export 65173:15 route-target import 65173:15

© 2006 Cisco Systems, Inc. All rights reserved. MPLS v2.2—5-7 What Is a VPN ID? A VPN identifier (VPN ID) allows you to identify VPNs by an ID number. –Not used to control distribution of routing information –Not used to associate IP addresses with VPN IDs in routing updates –Is stored on the VRF structure for a VPN Has the following elements: –OUI (three-octet hex number) –A VPN index (four-octet hex number identifying VPN within the company) Configure all PE routers that belong to the same VPN with the same VPN ID Make the VPN ID unique to the service provider network

© 2006 Cisco Systems, Inc. All rights reserved. MPLS v2.2—5-8 ip vrf vrf-name Router(config)# Configuring VPN IDs vpn id oui:vpn-index Router(config-vrf)# This command assigns the VPN ID to the VRF. This command creates a VRF routing table and a CEF forwarding table and enters VRF configuration mode.

© 2006 Cisco Systems, Inc. All rights reserved. MPLS v2.2—5-9 ip vrf forwarding vrf-name Router(config-if)# This command associates an interface with the specified VRF. The existing IP address is removed from the interface when the interface is put into VRF—the IP address must be reconfigured. CEF switching must be enabled on the interface. ip cef ! interface serial 0/0 ip vrf forwarding Customer_ABC ip address Sample router configuration: Assigning an Interface to a VRF Table

© 2006 Cisco Systems, Inc. All rights reserved. MPLS v2.2—5-10 MPLS VPN Network Example The network supports two VPN customers. Customer A runs RIP and BGP with the service provider; customer B uses only RIP. Both customers use network

© 2006 Cisco Systems, Inc. All rights reserved. MPLS v2.2—5-11 MPLS VPN Network Example (Cont.)

© 2006 Cisco Systems, Inc. All rights reserved. MPLS v2.2—5-12 Summary There are four required VRF configuration tasks: Create a VRF table: –Use the ip vrf command Assign RD to the VRF: –Use the rd command Specify export and import RTs: –Use the route-target command Assign interfaces to VRFs. –Use the ip vrf forwarding command and reconfigure the IP address Configuring a numeric VPN ID is optional. –Use the vpn id command

© 2006 Cisco Systems, Inc. All rights reserved. MPLS v2.2—5-13