I have the follow GNS3 network which you may recognise from the MPLS Fundamentals CBT Nugget series with Keith Barker:
R1 and R5 are PE routers. R2-R4 are P routers. All CBT and ACME routers are CE routers.
Ignore the blue CBT sites for now. I am trying to investigate the lo0 route on the top left green ACME_1 router (172.16.101.50/32), as seen by R5 - the PE router on the far right side of the MPLS network.
Everything works as described in the nugget but I can't help but notice that when I enter the show mpls forwarding-table vrf 101:ACME there is no label for the 172.16.101.50/32 network in the output:
R5#sh mpls forwarding-table vrf 101:ACME
Local Outgoing Prefix Bytes Label Outgoing Next Hop
Label Label or Tunnel Id Switched interface
507 No Label 192.168.111.2/32[V] \
26042 Fa2/0 192.168.202.2
508 No Label 192.168.202.0/30[V] \
511 No Label 184.108.40.206/32[V] 1800 Fa2/0 192.168.202.2
The network is in the bgp vpnv4 label table and all the routing works fine:
R5#show bgp vpnv4 unicast vrf 101:ACME labels
Network Next Hop In label/Out label
Route Distinguisher: 220.127.116.11:1 (101:ACME)
18.104.22.168/32 192.168.202.2 511/nolabel
172.16.101.0/30 22.214.171.124 nolabel/107
172.16.101.50/32 126.96.36.199 nolabel/108 <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
192.168.111.2/32 192.168.202.2 507/nolabel
192.168.202.0/30 0.0.0.0 508/nolabel(101:ACME)
But should I not also see an entry for this route in the show mpls forwarding-table vrf 101:ACME output? I understand that the VPN label will be the bottom label and that the top label (that is actual swapped by the P routers as the packet traverses the network) is going to be based on the next hop (188.8.131.52) and will this be R4's LDP advertised local label, but I would have though that this 172.16.101.50/32 network would show up as well...
Again, this is a technical query rather than a problem that needs solving. The whole network is functioning well. I think I'm just misunderstanding a fundamental idea here.
Thanks in advance :)