Nokia Lab | LAB 5 RSVP-TE basic |


RSVP-TE is a complex and wide range topic. I'm starting with RSVP-TE basic configuration and control plane processes - label signaling, session maintaining, timers, interaction between RSVP-TE and IGP. The next labs cover CSPF, Resource reservation, Resiliency.

Please check my first lab for input information.

Topology example

Lab tasks and questions:
  • basic RSVP-TE configuration
    • what we need for RSVP-TE infrastructure?
      • configure IGP with TE extension (e.g. OSPF)
      • add all p2p and "system" interfaces to MPLS and RSVP context
        • Do routers establish RSVP-TE adjacency? Why?
  • protocol operation
    • create LSP from R1 to R6 with an "empty" path
      • examine LSP signaling process(use debug or Wireshark)
        • capture PATH and RESV messages and examine their content
          • describe label signaling process
            • examine PSB and RSB (see "useful debug commands" section)
        • How do routers refresh RSVP sessions? What messages do they use?
        • How do routers maintain RSVP adjacency? What message do they use?
      • examine LSP tearing down process
        • break some link with active RSVP session and capture PathTear and ResvTear messages
          • describe tearing down process and message purpose
      • RSVP-TE timers
        • break some link with active RSVP session (e.g. LSP to_R6)
          • examine LSP on Head-end and check LSP  operation status
            • What is LSP operation status?
            • When does Head-end start signal LSP again?
              • describe the purpose of the retry timer
        • resignal timer
          • What is the purpose of the resignal timer?
            • What is the default value of the resignal timer?
            • Try to change the default timer and examine Head-end behavior. (Resignal timer has more value in the case with CSPF setup. I will return to this point in the next labs)
    • create LSP from R6 to R1 with "explicit" path - R6 - R5 - R3 - R4 - R2 - R1
      • examine label signaling process in this case
        • What is the purpose of the ERO?
        • What is the difference between ERO and RRO?
    • RSVP-TE and IGP interaction (no CSPF case)
      • Let's look at LSP from R1 to R6 with loose path
        • e.g. it may have path R1 - R2 - R4 - R6
        • try to increase IGP metric (e.g. link metric toward R4 on R2 )
          • examine LSP status on Head-end
            • What is LSP operation status?
          • describe interaction between RSVP-TE and IGP
      Final configs
      Github project

      Useful debug commands
      show router ospf opaque-database detail
      show router rsvp session detail
      show router mpls lsp detail
      show router mpls path detail
      tools dump router te-database detail
      tools dump router mpls te-lspinfo detail
      tools dump router rsvp psb detail
      tools dump router rsvp rsb detail