Routing

last person joined: 2 days ago 

Ask questions and share experiences about ACX Series, CTP Series, MX Series, PTX Series, SSR Series, JRR Series, and all things routing, including portfolios and protocols.
  • 1.  no-cspf

    Posted 09-02-2013 01:52
      |   view attached

    Hi experts,

     

    I would like to know what is the significance of  the  command "no-cspf"  while Configuring RSVP-Signaled LSPs? To my understanding RSVP based tunnels are created, based on CSPF  parameters  (User constraint+ resource constraint). Now suppose if we are configuring LSP by  disabling the CSPF, how tunnel with the absence of CSPF and adhering to user defined requirements ? Any clues? I am posting the URL for your reference.

     

    http://www.juniper.net/techpubs/en_US/junos10.4/topics/example/mpls-security-rsvp-signaled-lsp-configuring-cli.html

     

    Regards

    Ranjeet Badhe

     

     

    Attachment(s)

    docx
    Disabling CSPF.docx   13 KB 1 version


  • 2.  RE: no-cspf
    Best Answer

    Posted 09-02-2013 07:00

    Hi Ranjeet,

     

    With CSPF enabled for TE tunnel: TE headend router run cspf  on the database and calculate the tunnel path by looking into the constraints for the tunnels (bandwidth, admin group etc.), if constraints for the path are not satisfied, tunnel will not be signed at all (head end router will not send the RSVP path message to tunnel destination).

     

    With no-cspf option for the TE tunnel: Headend router will send the path message to the next hope router if the constraints for the path are satisfied between head end the next hop router, NEXT router will again process and pass the RSVP path message to next to next hop router if the next hop for the tunnel destination satisfy the TE constraints. If TE constraints are not satisfied router will send the RSVP PATH ERROR message to head end router and TE singling will fail.

     

    More details can be found in TE chapter of JNCIE study.

     

    https://www.juniper.net/us/en/training/certification/JNCIE_studyguide.pdf

     

    Regards

    Satinder Singh



  • 3.  RE: no-cspf

    Posted 09-02-2013 23:10

    Hello Satinder,

     

    That means tunnel will be established by verifying resources availability between 2 hops i.e. between the upstream router and the head end.  What do we accompolish using this method? Under which circumstances we will configure "no-cspf" option? 

     

    Since this option may have more tunnel set up time because this method is based on the hop-by-hop method comapred to tunnel set up initiated by Head end resource computing , what are teh advantages this method will provide over the previous one?



  • 4.  RE: no-cspf

    Posted 09-03-2013 00:31

    Hi,

     

    no-cspf option is used in number of cases.

     

    1. In case we need inter area (ospf) or inter level (isis) TE tunnel.

    2. Planning to implement the TE tunnel without enabling enabled TE extension in IGP.

    3. For troubleshooting purpose.

     

    Regards

    Satinder SIngh



  • 5.  RE: no-cspf

    Posted 09-03-2013 00:39

    Satinder thanks for your help. your explanation was very useful.



  • 6.  RE: no-cspf

    Posted 01-22-2016 02:10

    Thanks so much for your detailed explaination.