Creating a VPNv4 route reflector

PE devices in a BGP or MPLS VPN share routes between each other using IBGP. This can be accomplished using a full mesh configuration or a route reflector can be used to simplify a networks topology and improve scalability. While the general concepts are the same for using Route Reflectors in a normal IBGP network as in an BGP or MPLS VPN, there are some differences. In addition, there are special conditions that apply when a route reflector is configured for normal IPv4 BGP traffic (IPv4) and for BGP or MPLS VPN traffic (VPNv4). The differences and special considerations are described in the following:

Special considerations when configuring a route reflector for both IPv4 and VPNv4:

• A VPNv4 route does not need to be installed in any VRF before being reflected.
• Route reflector configurations for IPv4 and VPNv4 are separated in different address family configurations.
• For a VPNv4 route installed to a VRF, the reflected VPNv4 route still carries the original RD and PA.
• When there is a route reflector configuration change, a warning message is displayed that requests the user to clear the neighbor session.

Specific commands for VPNv4 - There are VPNv4 specific commands that must be configured to configure a route reflector for a BGP or MPLS VPN under address family VPNv4. A route reflector can be configured on a PE for IPv4 and VPNv4 or for either exclusively. When the user is configuring a route reflector for a BGP or MPLS VPN, the user must configure it specifically using the VPNv4 specific commands.

To create a VPNv4 route reflector with a client at the IP address 10.11.11.2, enter the following commands at the VPNv4 level of BGP Config level.

(config-bgp-vpnv4u)# neighbor 10.11.11.2 route-reflector-client

Note

You must follow the same considerations and create a VPNv6 route reflector also.