Routing

 View Only

IMPORTANT MODERATION NOTICE

This community is currently under full moderation, meaning  all posts will be reviewed before appearing in the community. Please expect a brief delay—there is no need to post multiple times. If your post is rejected, you'll receive an email outlining the reason(s). We've implemented full moderation to control spam. Thank you for your patience and participation.



  • 1.  External (Type 5) Route Summarization in OSPF

    Posted 09-28-2012 11:29

    I am trying to find a way to summarize routes "redistributed" from another IGP, say RIP, into OSPF.

     

    For example, if I had an ASBR in Area 0 redistributing 100.100.0.0/24, 100.100.1.0/24, 100.100.2.0/24 and 100.100.3.0/24 from RIP to OSPF, I only want to advertise the 100.100.0.0/22 Type-5 LSA into the backbone.

     

    This is possible in IOS with the use of the "summary-address" command.

     

    So far as I can tell, Junos only does summarization at ABRs using "area-range" or "nssa area-range" commands.

     

    Is this even possible in Junos, to do this on the ASBR itself?

     

    Thanks,

     

    Nic


    #ospf
    #iostojunos
    #summarization


  • 2.  RE: External (Type 5) Route Summarization in OSPF
    Best Answer

    Posted 09-28-2012 12:05
    good question.
    I also struggled with this one some time back. Here is an excellent blog entry that explains it:

    http://noshut.blogspot.in/2012/03/ospf-external-route-summarization.html


    HTH
    #ASBR
    #ospf
    #lsa
    #summarization


  • 3.  RE: External (Type 5) Route Summarization in OSPF

    Posted 09-28-2012 12:35

    Thanks, that was helpful.

     

    The salient points that I carried away are as follows, can someone verify -

     

    1. No specific IOS equivalent "summary-address" command

    2. Create an aggregate/generated route covering the desired routes

    3. Instead of importing the IGP routes in the routing policy, import the aggregate/generated route

     

    Would this workflow be the only possible way or does someone have a more streamlined flow?

     

    Thank again,

     

    Nic


    #ospf
    #iostojunos
    #summarization


  • 4.  RE: External (Type 5) Route Summarization in OSPF

    Posted 09-29-2012 02:10

    As of my understanding you are correct. 



  • 5.  RE: External (Type 5) Route Summarization in OSPF

    Posted 09-29-2012 08:18
    yes, you're right. There is no single command that will summarize OSPF external routes on the ASBR.
    The workaround mentioned on that blog post works fine though.


  • 6.  RE: External (Type 5) Route Summarization in OSPF

    Posted 06-23-2013 12:48

    You could convert the area to nssa and then apply area-range command under the nssa stanza on the ABR, that will summerize external routes.