From: Anthony Pace (anthonypace@xxxxxxxxxxx)
Date: Tue Jul 23 2002 - 17:43:37 GMT-3
This helps alot! "no-redistribution" inocculates the NSSA from the
External routes while allowing the ASBR/ABR to shoot them into Area-0.
The other aspects of the NSSA remain consistant:
NSSA (vanilla): no 0.0.0.0 from Area-0 ABR. ASBR's foreign routes are 7
in NSSA and go into Area-0 as 5
NSSA no-summary : like a total-stub, NSSA gets a 0.0.0.0 from Area-0
ABR (LSA-3)
NSSA default-info-originate , NSSA gets a 0.0.0.0 from Area-0 ABR
(LSA-7)
Anthony Pace
On Tue, 23 Jul 2002 13:30:50 -0700, "ccie candidate" <ccie1@lycos.com>
said:
> no-redistribution option is to prevent the ABR/ASBR from redistributing
> routes into the NSSA (remember this is a stub area anyway ). the ABR
> will still convert those routes into LSA5 and send them inside the OSPF
> domain , but not inside the NSSA itself .
>
> if you dont use the no-summary option with the no-redistribution , then
> you may have to use default-route-originate to propagate a default
> route inside your NSSA .( if no-summary is not used , this default will
> not propgate )
>
> i hope this helps .
>
>
>
>
>
>
> --
>
> On Tue, 23 Jul 2002 19:57:17
> Anthony Pace wrote:
> >Is this correct: If you had an ASBR which was an ABR and used NSSA with
> >"no-redistribute" you would stop the LSA-7 routes from being pushed
> >into downstraem routers of the NSSA but the LSA-7 routes would go into
> >Area-0 and change into LSA-5 and the NSSA could still get the "LSA-3
> >0.0.0.0" via this ABR if the "no-summary" was used?
> >
> >OR are you saying that "no-redistribution" simply keeps the LSA-7
> >routes from going into area 0, thereby isolating them to the NSSA? (in
> >which case I understood it backwards)
> >
> >Anthony Pace
> >
> >
> >On Mon, 22 Jul 2002 13:00:50 -0700, "ccie candidate" <ccie1@lycos.com>
> >said:
> >> ok ;
> >> the NSSA is similar to stub area , where only LSA3 (inter-area ) can
> >> propagate inside the area , No LSA4 $ 5 is allowed.
> >> teh diffrenece is that when you have another routing protocol
> >> redistributing into the ospf domain ( something like rip or redist
> >> static ) and the redistributio point is one of the down stream routers
> >> of the NSSA , then an LSA7 will also propagate inside the area , when
> >> it reaches the ABR (which is propably connected to area 0) it gets
> >> converted into LSA5 and propagate inside the domain .
> >>
> >> here are some tips .
> >> 1-NSSA is does not propagate default route back to the down steam
> >> routes unless you add NO-Summary option
> >> area 30 nssa no-summary
> >>
> >> 2-when you have the ABR is also ASBR , you have another two options for
> >> that command
> >>
> >> no-redistribution , will not allow the router to convert lsa7 to lsa5
> >>
> >> default-orginate , will propagate a default when the no-summary is not
> >> used .
> >>
> >> hope this helps
> >>
> >>
> >>
> >> --
> >>
> >> On Mon, 22 Jul 2002 11:28:21
> >> Khurram Khani wrote:
> >> >Look for scenario when NSSA ABR is also ASBR. It generates both Type 5 an
d
> >> >Type 7 LSAs.
> >> >
> >> >Thanks
> >> >Khurram
> >> >----- Original Message -----
> >> >From: "Louis Young" <tonyblair@etang.com>
> >> >To: <ccielab@groupstudy.com>
> >> >Sent: Monday, July 22, 2002 2:25 AM
> >> >Subject: Any tips when doing OSPF NSSA stuff?
> >> >
> >> >
> >> >> Hi all ,I was bewildered by some senarios about OSPF NSSA stuff,anyone
can
> >> >offer some general tips?
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