Nokia Lab | LAB 4 LDP |

Hi!

Move forward to MPLS stack. The first one is LDP.  I make emphasis on LDP session process and interaction between LIB and LFIB. I recommend you use traffic dumps and debug for investigation. 

Please check my first lab for input information.

Topology example

Lab tasks and questions:

• Basic LDP
• prepare basic and IGP configuration (Multi-area OSPF, area type - normal, add "system" to OSPF)
• enable LDP on P2P interfaces
• LDP session
• examine LDP neighbor discovery process
• What is the destination IP address of Hello messages?
• examine LDP session establishment
• What address does SR-OS router use as a transport address for LDP control plane?
• examine Label exchange
• What label mapping does SR-OS router generate by default?
• LIB and LFIB
• examine LIB and LFIB
• What is the difference between LIB and LFIB?
• configure ECMP 2 (e.g. on R1) and examine RT, LIB and LFIB
• Export policy and summarization
• create two additional loopback interfaces on R1 with addresses from the same subnet (e.g. 172.16.0.0/32, 172.16.0.1/32)
• export prefixes to LDP by policy
• examine LFIB on R2
• Does it contain entries with target prefixes? What about LIB?
• What is the reason for this difference?
• add loopback interfaces to OSPF
• examine LIB and LFIB on R2
• examine LFIB on R5 or R6
• Does it contain entries with target prefixes?
• summarize these prefixes from area 0 on R3 and R4
• examine LFIB on R5 or R6
• Does it contain entries with target prefixes?
• How can we resolve this issue?

Final configs
Github project

Useful debug commands

show router ldp session

show router ldp bindings

show router ldp bindings active

show router fp-tunnel-table 1 {prefix}