From: Ravi (s_ravichandran@xxxxxxxxxxx)
Date: Sun Jul 01 2001 - 10:47:08 GMT-3
What is your transit area ? is area 1 or area 3?
----- Original Message -----
From: Wei Man <mandraw1@yahoo.com>
To: Ravi <s_ravichandran@hotmail.com>; <ccielab@groupstudy.com>
Sent: Sunday, July 01, 2001 9:31 AM
Subject: Re: OSPF Concept Question
> From my Lab, ospf cost R3 back to back connection with
> R1 is greater than from R3-R2-R1.
> so in theory, it should use R3-R2-R1 . In my lab
> it is still using R3-R1 back to back connection.
> According to OSPF Network Design Solution
> page 235 (Controlling Inter-Area Traffic)
> One of the condition of OSPF Traffic selection is
> "Use the ABR closest to the destination of traffic"
>
> so which one does have more priority ?
> "Use the ABR closest to the destination of traffic" or
> "total ospf cost to destination"
>
>
> --- Ravi <s_ravichandran@hotmail.com> wrote:
> > It depends on the total cost from host A to R4. OSPF
> > will choose the route
> > with lowest cost. So in your case R4 has two route
> > to host A. Now ospf will
> > check the cost and decide the best route. If it has
> > equal cost then it will
> > do load balance. You can also manipulate the cost of
> > a link and choose the
> > route that you would prefer.
> >
> > Regards,
> > Ravi
> > ----- Original Message -----
> > From: Wei Man <mandraw1@yahoo.com>
> > To: <ccielab@groupstudy.com>
> > Sent: Sunday, July 01, 2001 7:41 AM
> > Subject: OSPF Concept Question
> >
> >
> > > I have question regarding how OSPF behave
> > > in selecting route
> > >
> > >
> > > A--R0--R1----R2----R3---R4
> > > \ /
> > > ----------
> > > Where R1 is connected back to back with R2
> > > using Serial 0
> > > and R1 is connected back to back with R3 using
> > > Serial 1
> > >
> > > A is host connected to R0 and is in Area 0
> > > Link R0 to R1 , OSPF Area 0
> > > Link R1 to R2 , OSPF Area 1
> > > Link R2 to R3, OSPF Area 2
> > > Link R3 to R4, OSPF Area 2
> > > Link R1 to R3, OSPF Area 3
> > >
> > > There is virtual link to between R0-R1 to R2-R3
> > > using Area 1 as transit area
> > >
> > > When R4 try to reach A, which Route R4 will use
> > > Is R4-R3-R2(Virtual Link)-R1-R0-A or
> > > R4-R3-R1-A ?
> > > Can somebody explain to me how route selection
> > > in ospf works in this case ?
> > >
> > > Thanks in advance
> > >
> > >
> > >
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