Objectives
The simulator ticks each one as soon as the network meets it.
On PE1, compare show ip route vrf CUST-A with show bgp vpnv4 unicast all, and note what is missing.
Fix the route-target mismatch so PE2 imports PE1’s customer routes.
Make PE2 advertise customer A’s LAN (its static route) into VPNv4.
Find the break in the label-switched path between PE1 and PE2 and repair LDP.
CE1 pings 192.168.2.1.
Before you start
Work through the layers: is the VPNv4 session up, are the routes exchanged, does each PE import them (the route targets must match), and is there an LSP to the remote PE loopback? show mpls ldp neighbor and show mpls forwarding-table show LDP neighbors and labels; show vrf detail is modeled as show vrf plus the running configuration.
Concept
Troubleshooting an MPLS L3VPN
An L3VPN needs three things to line up: the VPN routes must be exported and imported (route targets), carried in BGP (redistribution into the VRF and VPNv4 sessions), and transported (an LDP label path between the PE loopbacks). Each fault breaks a different layer.
Concept
BGP/MPLS Layer 3 VPN
An L3VPN carries each customer’s routes in its own routing table (VRF / VPN instance) on the provider edge, and moves their packets across a shared core with two MPLS labels. The core routers see only labels, never customer addresses.
