From: Huizinga, Rene (rhuizinga@upcbroadband.com)
Date: Thu Aug 10 2006 - 20:40:37 ART
Maybe I'm wrong now, but I have in a production-network a small NSSA-area,
no-summary defined (also no-redistribution, just want to get prefixes
out..), with only one ABR which does AND the type-7 to 5 translation but
because of the no-summ does NOT re-advertise this back into the NSSA and
leaves the type-7's advertised, but very well into the backbone...so maybe
simply reconfiguring your both ABR's to no-summary would already solve the
issue ? Maybe give it a try...
Cya
Rene.
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Victor Cappuccio
Sent: Friday, August 11, 2006 1:07 AM
To: 'nikolai'; 'Cisco certification'
Subject: RE: OSPF NSSA issue
What you see is a normal operation defined in this RFC
http://www.faqs.org/rfcs/rfc1587.html
4.1 Translating Type-7 LSAs Into Type-5 LSAs
This step is performed as part of the NSSA's Dijkstra calculation
after type-5 and type-7 routes have been calculated. If the
calculating router is not an area border router this translation
algorithm should be skipped. All reachable area border routers in
the NSSA should now be examined noting the one with the highest
router ID. If this router has the highest router ID, it will be the
one translating type-7 LSAs into type-5 LSAs for the NSSA, otherwise
the translation algorithm should not be performed.
HTH
Victor.-
-----Mensaje original-----
De: nobody@groupstudy.com [mailto:nobody@groupstudy.com] En nombre de
nikolai Enviado el: Jueves, 10 de Agosto de 2006 05:25 p.m.
Para: Cisco certification
Asunto: OSPF NSSA issue
I have an interesting OSPF NSSA issue. Two routers, both ABRs (Area 0 and
NSSA no-summary), are receiving the same prefix as Type-7 from two ASBRs in
the NSSA area. Both ABRs have the prefix as two Type-7s from both ASBRs, and
a single Type-5 from only one ABR in their OSPF LSA dB.
However, the ABR advertising the Type-5 has both Type-7s in its RIB, while
the other ABR has only the single Type-5 in its RIB. Please see
http://nikolai.pastebin.ca/125715 for more details.
My objective was to get both paths to the prefix in the RIB as ECMP, and I
was able to achieve that by turning the NSSA into a regular area, thus
eliminating the Type-7 Externals, and dealing with Type-5 only. However,
would love to go back to NSSA no-summary, if possible.
Thanks for the help,
-- nikolai
This archive was generated by hypermail 2.1.4 : Fri Sep 01 2006 - 15:41:56 ART