what protocols we have to run before runing MPLS VPN

[aurangzab]

I am new to MPLS VPN.i want to implement MPLS based VPN. i ve read many documents on MPLS VPN configuration but when they implement MPLS VPN they donot use "IP MPLS" (which is used when v want to run only MPLS command) through out the configration.

Why they do not use IP MPLS command when they are estabilishing MPLS VPN.

In all MPLS VPN configuration manual, does they assume that MPLS is already running coz they r not typing IP MPLS command.

Pls tell me necessary actions (in short)that i must take before configuring MPLS VPN.

thank you

[Harold Ritter]

The assumption is probably the LDP/TDP or TE Tunnels are already configured in the core.

Here's a few things you need in order to run MPLS VPN:

- Any IGP will do (unless you use TE Tunnels, in which case ospf or isis is required). You should make sure that the loopback interfaces of all PE routers are advertised via the IGP.

- LDP, TDP or RSVP/TE running in the core. LDP and TDP are enabled with the "mpls ip". RSVP is used to signal LSP if you configure MPLS TE Tunnels between the PEs. If you decide to go with MPLS TE, you then need to use ISIS or OSPF as the IGP since only these two support TE.

- MPBGP configured on the PEs (address-family vpnv4). This is used to carry VPNv4 updates between the PEs.

- VRF globally configured on the PEs and on the interfaces to the CE routers.

- CEF must be configured on all core routers. MPLS requires CEF to be active.

This is by no mean a extensive list but should give you an idea of what is required to get MPLS VPN to work.

Hope this helps,