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 [email protected].
Dig Deeper on WAN technologies and services
Related Q&A from Rainer Enders
Rainer Enders explains how to allow certain users to access a VPN client while restricting others. Continue Reading
In this Ask the Expert response, Rainer Enders explains how to disable VPN passthrough and what the benefits and drawbacks are. Continue Reading
Our VPN expert explains why a Layer 3 VPN can ping but not do a tracepath from the client in this response. Continue Reading