Now that the final configuration is complete, and the VPN routes are propagated across the SuperCom backbone, you can learn how to examine the MPLS label assignment and which labels are present in the label stack.
Figure 9-13 shows a portion of the example topology, which you can use to identify this label assignment. The EuroBank Paris site injects subnet 126.96.36.199/24 into the MPLS/VPN backbone, which is advertised subsequently to the EuroBank San Francisco site. The figure shows the relevant label assignments, and you can see the relevant IOS commands to see these assignments in the examples that follow.
From the perspective of the SuperCom San Jose PE-router, you can see in Example 9-25 that you can use the show ip bgp vpnv4 vrf-name tags command to identify which VPN tag is assigned (by the originating PE-router) to the route. In the example, a tag of 38 is assigned to subnet 188.8.131.52/24. You can see this by examining the Out tag field in the command output.
San Jose# show ip bgp vpnv4 vrf EuroBank tags Network Next Hop In tag/Out tag Route Distinguisher: 1:27 (EuroBank) 10.2.1.0/24 0.0.0.0 38/aggregate(EuroBank) 184.108.40.206 220.127.116.11 notag/38
The BGP next-hop for the 18.104.22.168/24 subnet is 22.214.171.124, which is the loopback address of the SuperCom Paris PE-router. This next-hop address was learned via the SuperCom IGP and, therefore, the show tag-switching forwarding-table command must be used to identify the IGP label that is used to forward any packets destined for the 126.96.36.199/24 subnet. Example 9-26 shows the output for this command for the SuperCom San Jose router and for the Washington P-router that is in the path to the Paris PE-router. The example also shows the forwarding table for the Paris PE-router and highlights the 188.8.131.52/24 subnet as a VPN route by the [V].
San Jose# show tag-switching forwarding-table Local Outgoing Prefix Bytes tag Outgoing Next Hop tag tag or VC or Tunnel Id switched interface 33 36 184.108.40.206/32 0 AT1/0/0.1 point2point 38 Aggregate 10.2.1.0/24[V] 3120 Washington# show tag-switching forwarding-table Local Outgoing Prefix Bytes tag Outgoing Next Hop tag tag or VC or Tunnel Id switched interface 36 Pop tag 220.127.116.11/32 9416 AT0/1/0.1 point2point Paris# show tag-switching forwarding-table Local Outgoing Prefix Bytes tag Outgoing Next Hop tag tag or VC or Tunnel Id switched interface 38 Aggregate 18.104.22.168/24[V] 1040