From: LB (lb.ccie@gmail.com)
Date: Thu Oct 05 2006 - 11:39:35 ART
So Scott:
If I issue the "no capability transit" command I can have a route through
the trully shortest path? And can I then filter routes etc thru that path?.
Can you point me out to literature on this?
Thanks,
-Leo
On 10/5/06, Scott Morris <swm@emanon.com> wrote:
>
> That won't work. Area 0 is necessary to exchange the LSAs. If you have
> only one area, nobody cares what the number is. If you have more than one
> area, you MUST have an area 0.
>
> While the packets don't technically have to transit that (not in your
> diagram), the LSA exchanges do. Otherwise you make things exponentially
> more complex at the database level. :)
>
> HTH,
>
>
> Scott Morris, CCIE4 (R&S/ISP-Dial/Security/Service Provider) #4713, JNCIE
> #153, CISSP, et al.
> CCSI/JNCI-M/JNCI-J
> IPExpert VP - Curriculum Development
> IPExpert Sr. Technical Instructor
> smorris@ipexpert.com
> http://www.ipexpert.com
>
>
>
> -----Original Message-----
> From: WorkerBee [mailto:ciscobee@gmail.com]
> Sent: Thursday, October 05, 2006 10:15 AM
> To: Scott Morris
> Cc: Leo Boulton; Cisco certification
> Subject: Re: OSPFv2 inter-area transit - fundamental concept
>
> Hi Scott,
>
> How does it work if I have the following setup where R2 is the ABR without
> Area 0?
>
> [R1]----(area 10)-------[R2]------(area 20)-----[R3]
>
> Without Area 0 define in any of R2 interface, R1 and R3 cannot communicate
> with each other. "no capability transit" at R2 does not help.
>
> Can you shine some light? :)
>
>
> On 10/5/06, Scott Morris <swm@emanon.com> wrote:
> > OSPFv2 actually allowed a workaround called a transit area, where ospf
> > will calculate the truly shortest path. You can turn this off with
> > "no capability transit" if you wish.
> >
> > :)
> >
> >
> > Scott Morris, CCIE4 (R&S/ISP-Dial/Security/Service Provider) #4713,
> > JNCIE #153, CISSP, et al.
> > CCSI/JNCI-M/JNCI-J
> > IPExpert VP - Curriculum Development
> > IPExpert Sr. Technical Instructor
> > smorris@ipexpert.com
> > http://www.ipexpert.com
> >
> >
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf
> > Of Leo Boulton
> > Sent: Thursday, October 05, 2006 9:01 AM
> > To: Cisco certification
> > Subject: OSPFv2 inter-area transit - fundamental concept
> >
> > Hi, and thanks:
> >
> > Simple question: Is it a restriction of OSPF that all inter-area
> > traffic must flow through the backbone area? What if I have two
> > non-backbone areas next to each other, does the traffic need to go to
> > the backbone and then to the other area? I was always under the
> > impression that this was not a requirement of OSPF.
> >
> > Thanks,
> >
> > -LB
> >
> > ______________________________________________________________________
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