V-217067

Discussion

The primary security model for an MPLS L3VPN infrastructure is traffic separation. The service provider must guarantee the customer that traffic from one VPN does not leak into another VPN or into the core, and that core traffic must not leak into any VPN. Hence, it is imperative that each CE-facing interface can only be associated to one VRF—that alone is the fundamental framework for traffic separation.

Check Content

Review the design plan for deploying L3VPN and VRF-lite. 

Review all CE-facing interfaces and verify that the proper VRF is defined. The example below depicts the CE-facing interface ge-0/1/0 bound to VRF titled L3VPN_CUST1. Notice that the PE router is peering OSPF with the CE router.

interfaces {
    …
    …
    …
    }
    ge-0/1/0 {
        description "link to Customer 1";
        unit 0 {
            family inet {
                address 101.3.44.6/30;
            }
        }
    }
    …
    …
    …
}

routing-instances {
    L3VPN_CUST1 {
        description "Between PE1 & PE2";
        instance-type vrf;
        interface ge-0/1/0.0;
        route-distinguisher 33:33;
        vrf-target target:33:33;
        vrf-table-label;
        protocols {
            ospf {
                area 0.0.0.1 {
                    interface ge-0/1/0.0;
                }
            }
        }
    }
}

If any VRFs are not bound to the appropriate physical or logical interface, this is a finding.