From: Carlos G Mendioroz (tron@huapi.ba.ar)
Date: Thu Oct 26 2006 - 07:08:25 ART
I was just pointing to the original question: why was that happening.
The leaking I mean.
Doing another area range seems simpler to me than making a tunnel,
but that's another issue.
The tunnel solution kind of obfuscated the root of the problem.
HTHT,
-Carlos
Brian McGahan @ 25/10/2006 21:01 -0500 dixit:
> Yes when you configure a virtual-link the remote router it
> terminates on becomes and ABR. Also you can summarize on just one side
> deliberately for the purpose of traffic engineering as well. While not
> related to this specific task suppose you have two ABRs between area 0
> and area 1 and you are doing the "area 0 range" command on 1 ABR. This
> would force traffic to route out the other exit point based on the
> longest match routing principle.
>
> HTH,
>
> Brian McGahan, CCIE #8593 (R&S/SP)
> bmcgahan@internetworkexpert.com
>
> Internetwork Expert, Inc.
> http://www.InternetworkExpert.com
> Toll Free: 877-224-8987 x 705
> Outside US: 775-826-4344 x 705
> 24/7 Support: http://forum.internetworkexpert.com
> Live Chat: http://www.internetworkexpert.com/chat/
>
>
>> -----Original Message-----
>> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
> Of
>> Carlos G Mendioroz
>> Sent: Wednesday, October 25, 2006 10:38 AM
>> To: Gene
>> Cc: cyucel@gmail.com; ccielab@groupstudy.com
>> Subject: Re: OSPF questions (IE VOL1 LAB7)
>>
>> Sorry for late update,
>> but isn't the case that when you set a virtual link between R5 and R1,
>> R1 becomes an ABR ? Then you should place the area range also at R1,
>> or else R1 will be injecting the /24 into A1.
>> So, I think, it's not R5 the one leaking the information, its R1!
>> -Carlos
>>
>> Gene @ 2/10/2006 10:56 -0500 dixit:
>>> Cagri-Try looking at the OSPF database in R3 before and after you
> set
>> up the virtual link. I think of it like this--if R1 is going to have
> an
>> interface in area 0 (and the virtual link endpoint is an interface in
> area
>> 0) then it has to know about everything area 0 knows. In particular,
> R1
>> needs to know about those unsummarized /24s.So how can R1 find out
> about
>> those? One way would be to encapsulate the routing updates from R5 to
> R1,
>> so that R3 doesn't see them. This is the GRE tunnel solution.Another
> way
>> is to populate R3's database with area 0 information, then pass that
> info
>> on to R1. This is the way the developers of OSPF chose to implement
>> virtual link. So in the virtual link solution R3 sees the /24s.Check
> the
>> database in R3 with and without the virtual-link and with and without
> the
>> tunnel.-gt--- On Mon 10/02, Cagri Yucel < cyucel@gmail.com >
>> wrote:From: Cagri Yucel [mailto: cyucel@gmail.com]To:
>> ccielab@groupstudy.comDate: Mon, 2 Oct 2006 12:27:44 +0100Subject:
>>
>>> OSPF questions (IE VOL1 LAB7)I am really confused with this one,
> below
>> is a quick diagramArea 0--------- R5 ---Area1-----R3
> ------Area1------R1--
>> ----Area2Two /24 ranges in area0 are summarised using R5 so they
> received
>> as a /23 onR3, no problems.Later we add Area2, then naturally a
> Virtual
>> Link between R5 and R1 fine,suddenly R5 starts to leak /24s to R3.Why
> is
>> this ? I am not talking about /24s coming from R1 which naturallyneed
> to
>> be summarised further.IE's solution for the problem is using a tunnel
> and
>> it works perfectly. Butwhat is the underlying logic ?Why VLINK leaks
>> routes at the first place and why tunnel avoids thatbehaviour.-
>>
> cagri___________________________________________________________________
> __
>> __Subscription information may be found at:
>> http://www.groupstudy.com/list/CCIELab.html
>>> _______________________________________________
>>> No banners. No pop-ups. No kidding.
>>> Make My Way your home on the Web - http://www.myway.com
>>>
>>>
> _______________________________________________________________________
>>> Subscription information may be found at:
>>> http://www.groupstudy.com/list/CCIELab.html
>>
> _______________________________________________________________________
>> Subscription information may be found at:
>> http://www.groupstudy.com/list/CCIELab.html
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Wed Nov 01 2006 - 07:29:06 ART