From: David Ham (ccieau@xxxxxxxxx)
Date: Fri May 03 2002 - 22:21:03 GMT-3
I think there are some ways to fix this problem. It
has been mentioned several time on past discussion.
First solution: introducing second ospf domain: here
are the steps:
1. add second ospf routing domain. eq ospf 2
2. redistribute first ospf routing domain ie ospf 1
to second ospf routing domain.
3. apply summary address
4. redistribute ospf 2 into igrp domain.
Second solution: adding an extra area and make ABR. (
in your case R3
1. clear a loopback interface and add network ____
area x on the ospf routing process.
2. R3 now becomes ABR/ASBR. Apply area 0 range ____
etc..
David Ham
--- Perminder Grewal <percy_gunner@hotmail.com> wrote:
> Can anyone help
>
>
> I tried this scenario in my lab yesterday the basic
> set up is the same as
> yours.
>
> > R4
> > |s0
> > |
> > --s0.1---| R1---|e0
> >|e0-R3< /
> > --s0.2---------<
> > \
> > R2---|e0
>
>
> 1) the frame is a /29 area 0 (r3 r2 r1)
> 2) R1 and R2 are ABR area 0 and area 1 (e0) /25
> 3) R3 to R4 is a /24 igrp. ASBR (area 0 and IGRP)
>
> A) I can summarise the /25 to a /24 and the routers
> R1 and R2 have a null0
> in the route table and R4 gets the /24 from area 1.
>
> B) I've done the same on R3 summarise /29 to a /24
> this does not put in a
> null0 in the R3 route table and in doing so does not
> advertise that prefix
> to R4.
>
> Solution??????
>
> I tried the the summ on R1 and R2 for area 0 it puts
> in the /24 nullO in
> there route table but R3 does not have it and in
> doing so does not advertise
> to R4.
>
> I got over the problem by including a static route
> /24 in R3 to null0 and
> then redistributed that static to in IGRP in doing
> so R4 gets the /24 for
> area.
>
> If anyone can shed any light, please let me know. I
> tried every combo last
> night and could only do this by the static method.
>
>
> Cheers
>
> Percy
>
>
>
>
> >From: Katson PN Yeung <kyeung@hkcix.com>
> >Reply-To: Katson PN Yeung <kyeung@hkcix.com>
> >To: ccielab@groupstudy.com
> >Subject: Solie's P.791 confusion.
> >Date: Fri, 03 May 2002 09:29:31 +0800
> >
> >Dear group,
> >
> >I have a question about Solie's book P.791.
> >
> >On the 2nd paragraph from the top, it saids:
> >"You cannot summarize Area 0 or the backbone area.
> All summaries are
> >flooded into area 0 and then are flooded out from
> that point. Therefore
> >Area 0 routes cannot be summarized"
> >
> >However, in the scenario such as below:
> >
> > R4
> > |s0
> > |
> > --s0.1---| R1---|e0
> >|e0-R3< /
> > --s0.2---------<
> > \
> > R2---|e0
> >
> >Where R3s0.2, R1s0, and R2s0 forming OSPF area 0
> (/28 subnet)
> >- R1e0 area 1 (/24)
> >- R2e0 area 2 (/24)
> >- R3e0 being area 3 (/24 or whatever)
> >- R3 s0.1 and R4 running igrp (/24)
> >
> >Isn't it easy (and convenient) to create a /24
> summary route by "area 0
> >range x.x.x.x 255.255.255.0" at R3, and then get it
> redistributed to igrp?
> >I did they before since the redis connected/summary
> ASBR method doesn't
> >work now.
> >
> >Solie P.791 makes me confused. Can someone
> clarifies if this "area 0
> >range" method is "okay to use" in the real lab
> environment?
> >
> >Or just like someone saids, tunnel method, sec
> interface method? or even
> >piggy-back OSPF
> >method are the more preferable way to make a /24
> summary route?
> >
> >Thanks a lot.
>
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