L3 multiprotocol label switching (MPLS) VPNs are based on routing tables . They use standard routing protocols, such as BGP, to create route maps and use various add-ons and extensions for the purpose of the L3 VPN, such as route distinguishers and route targets to differentiate and properly handle routes and destinations.
The multiprotocol extensions of BGP used for MPLS VPN services are only defined for BGP-4 as far as I know. So BGP-4 support would be required.
Email your VPN-related questions to firstname.lastname@example.org.
This was first published in February 2012