Clarification in NSSA

Krishna Rao <ospf_query@REDIFFMAIL.COM> Fri, 27 June 2003 06:28 UTC

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Date: Fri, 27 Jun 2003 06:19:33 -0000
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From: Krishna Rao <ospf_query@REDIFFMAIL.COM>
Subject: Clarification in NSSA
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I am basically testing RFC 3101 NSSA implementation. I find that
routes are missing in the Router (not in NSSA area) but is
conected to the Router in NSSA area through backbone area.

Topology Used in Testing
  |                               |
  |                               |
  |                               |
                 |                |
                 |                |
                 |                |
            --------------------------- NSSA area
                        | area
                        |Import External Routes.

There are 2 areas in this Topology -
NSSA area (R2, R3 and R4)
Remaining all the networks are in backbone area.

R1 is connected to R2 and R3 through backbone area. R2 and R3 are
connected through backbone area.

RouterID of R1
RouterID of R2
RouterID of R3

R3 is elected as Translator. Import external routes at R4. R1
holds the external routes.

Now, stop the router R3. R2 takes over as Translator.

BUT, now R1 doesnot hold the external routes.

I expect the R1 to hold the external routes. But as per RFC 3101
since R2 holds LSA generated by R3 which is of higher RouterID, R2
doesnot generate Type 5 LSAs. Is it correct. If this is the case,
then R1 would never hold the external routes.

Your response on this would be highly appreciated.

Thanks & Regards

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