Re: 3 OSPF non-zero areas

Dear,
I think building tunnel between direct-connected router makes no sense,
otherwise you build tunnel between any two indirectly connected router.
But,anyhow this is not the case. I'm afraid tunnel in your scenario may
causes things more complicated. What you need is just make a zero 0
area.here is how:

Make a loopback interface at R2 in area 0, than build a virtual link between
R2 and R3.Then everything goes right.

the point is:
Since R2 is connected directly with R1 and R3, Area 3 and Area 4 are
connected to Area 0, the only area that is seperated is area 5, so making a
virtual link makes Area 5 also connected with area 0 is the solution.

regards.

2009/5/6 Roy Waterman <roy.waterman_at_gmail.com>

> Ah I assumed he meant that R1 was connected to Area 0.
> If he didn't mean that, then this is the end of my participation in this
> thread :)
>
> 2009/5/6 Anthony Sequeira <asequeira_at_internetworkexpert.com>
>
> > I think Anantha is really going "outside the box" here as he has NO area
> 0
> > at all.
> >
> > It is really late for me, but I am thinking the only time we can go
> without
> > an Area 0 in OSPF is when we only have a single area.
> >
> > Warmest Regards,
> >
> > Anthony J. Sequeira, CCIE #15626
> > Senior CCIE Instructor
> > http://www.InternetworkExpert.com
> >
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> >
> > Test your Core Knowledge today!
> > Q: What is the BGP synchronization rule?
> > A: This rule states that a router will not use or advertise a route
> learned
> > by IBGP until a matching route has been learned from an IGP.
> > More Info:
> >
> www.cisco.com/en/US/docs/ios/12_2/ip/configuration/guide/1cfbgp.html#wp1002910
> >
> >
> > On May 6, 2009, at 1:01 AM, Roy Waterman wrote:
> >
> > Sorry what i meant to say was:
> >>
> >> You can create a virtual link to extend area 0 to area 4, and then
> create
> >> a
> >> 2nd virtual link to extend area 0 (which was extended to area 4) to area
> >> 5.
> >>
> >> 2009/5/6 Roy Waterman <roy.waterman_at_gmail.com>
> >>
> >> Hi Anantha
> >>> You can create a virtual link to extend area 0 to area 4, and then
> create
> >>> a
> >>> 2nd virtual link to extend area4 to area 5.
> >>>
> >>>
> >>> 2009/5/6 Anantha Subramanian Natarajan <
> anantha.natarajan_at_gravitant.com>
> >>>
> >>> Hi All,
> >>>
> >>>>
> >>>> Is it possible to run OSPF when there are three OSPF areas as shown
> >>>> below
> >>>> and none of them is not a area 0.
> >>>>
> >>>> R1 --ospf area3 --R2 ---ospf area4 ---R3 ----ospf area5 --R4
> >>>>
> >>>> My understanding is that, virtual-link would be only useful when to
> join
> >>>> a
> >>>> non-zero area to connect to area0 which is seperated by another
> >>>> non-zero area.Also the virtual links would be useful in case where
> area
> >>>> 0
> >>>> is
> >>>> broken in between a non-zero area.Assuming my above understanding is
> >>>> right,I
> >>>> am thinking the above scenario will not be able to use virtual links
> to
> >>>> propagate OSPF routes among R1,R2,R3,R4.
> >>>>
> >>>> In this case,if I would be able to build GRE tunnel between
> >>>> R1-R2,R2-R3,R3-R4 and run OSPF on area0 over them,In that case,will
> the
> >>>> OSPF
> >>>> routes would be able to get propagated ?
> >>>>
> >>>> Thanks for the help
> >>>>
> >>>> Regards
> >>>> Anantha Subramanian Natarajan
> >>>>
> >>>>
> >>>> Blogs and organic groups at http://www.ccie.net
> >>>>
> >>>>
> _______________________________________________________________________
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> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>
> >>> --
> >>> Regards
> >>> Roy
> >>>
> >>>
> >>
> >>
> >> --
> >> Regards
> >> Roy
> >>
> >>
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> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >
>
>
> --
> Regards
> Roy
>
>
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Received on Wed May 06 2009 - 14:29:12 ART