[j-nsp] OSPF NSSA Type 4 LSA generation behavior

[Muruganandham M]

I think the behavior which you said is also not compliant with the RFC
mentioned.

However my opinion is that, the ABR who is doing the conversion will set the
E bit in its router LSA on area 0; by seeing this router LSA the other ABRs
connected to the Area 0 will generate the ASBR summary and flood it to their
connected non-area-zero routers.

I dont see a reason for the NSSA ABR to generate a type-4 LSA within Area 0.


Please correct me if i am wrong.

Thanks.
Muruganandham

On Tue, Apr 19, 2011 at 5:34 PM, Adam <adam.tajer at gmail.com> wrote:

> If I recall correctly, the ABR that translates Type7 into Type5
> (highest RID) shows up in the backbone and other non-backbone areas as
> ASBR, because it changes the Advertising router to itself while
> performing translation from Type 7 and generating Type5 into Area 0.
> So in areas other than the NSSA (where prefix was injected), you
> should not see the "real" ASBR as Advertising Router, you should see
> the ABR that performed the 7-to-5 translation listed in that field.
>
> Regards,
> Adam
>
> On Tue, Apr 19, 2011 at 4:08 PM, Muruganandham M <sedhuanand at gmail.com>
> wrote:
> > Dear Experts,
> >
> >        As per RFC 3101, *The OSPF Not-So-Stubby Area (NSSA) Option*,
> listed
> > in the Juniper supported standards,
> >
> > Since Type-5 AS-external-LSAs are not flooded
> >   into NSSAs, NSSA border routers should not originate Type-4 summary-
> >   LSAs into their NSSAs.  Also an NSSA's border routers never originate
> >   Type-4 summary-LSAs for the NSSA's AS boundary routers, since Type-7
> >   AS-external-LSAs are never flooded beyond the NSSA's border.
> >
> > This looks to be the same behavior in CISCO also.
> >
> > But JUNIPER router (ABR) does generate the ASBR summary (type 4) for
> > the NSSA ASBR.  Is there any specific  reason for doing this
> > implementation? Or Juniper follows any other RFC for this behavior?
> >
> > --
> > Thanks
> > Muruganandham M
> > _______________________________________________
> > juniper-nsp mailing list juniper-nsp at puck.nether.net
> > https://puck.nether.net/mailman/listinfo/juniper-nsp
> >
>



-- 
Thanks
Muruganandham M