I have a loopback interface in my LSR. The directly connected interface and the loopback interface (which is again a directly connected interface) doesn't have a LFIB entry in my router. Although there is a LIB entry as imp-null for the directly connected interfaces. Am looking for pointers to understand this behaviour.
Output:
PE2#sh ip int brief
Interface IP-Address OK? Method Status Protocol
FastEthernet0/0 172.16.56.6 YES NVRAM up up
FastEthernet0/1 192.168.1.2 YES NVRAM up up
FastEthernet1/0 192.168.2.2 YES NVRAM up up
FastEthernet2/0 unassigned YES NVRAM administratively down down
Loopback0 6.6.6.6 YES NVRAM up up
PE2#sh mpls ldp bindings 6.6.6.6 32
tib entry: 6.6.6.6/32, rev 4
local binding: tag: imp-null
remote binding: tsr: 5.5.5.5:0, tag: 17
PE2#sh mpls forwarding-table
Local Outgoing Prefix Bytes tag Outgoing Next Hop
tag tag or VC or Tunnel Id switched interface
16 16 4.4.4.4/32 0 Fa0/0 172.16.56.5
17 Pop tag 5.5.5.5/32 0 Fa0/0 172.16.56.5
18 18 172.16.34.0/24 0 Fa0/0 172.16.56.5
19 Pop tag 172.16.45.0/24 0 Fa0/0 172.16.56.5
20 20 3.3.3.3/32 0 Fa0/0 172.16.56.5
21 Untagged 8.8.8.8/32[V] 1242 Fa1/0 192.168.2.1
22 Aggregate 192.168.2.0/24[V] 0