Re: EIGRP - Split Horizon

I believe the key word is out of the "interface" the route was learned from.
R4 sure receives the route from R2 also - same route but different metric
and path - check the topology table, you will sure see that they have
different metrics

On Sat, Jan 8, 2011 at 10:05 AM, Scott M Vermillion <
scott_ccie_list_at_it-ag.com> wrote:

> Hey Dave,
>
> There's a nuance in the description of EIGRP split horizon in the
> command ref:
>
>
> http://www.cisco.com/en/US/docs/ios/iproute_eigrp/command/reference/ire_s1.html#wp1058799
>
> "The split-horizon rule prohibits a router from advertising a route
> through an interface that the router itself uses to reach the
> destination."
>
> I'm guessing neither R3 nor R4 use the other to reach R1's Lo0, correct?
>
> Cheers,
>
> Scott
>
>
>
> On Jan 8, 2011, at 10:54 , Dave Serra wrote:
>
> > Hi Guys,
> >
> > I thought I understood the split horizon rule until I built the
> > following topology in GNS:
> >
> > R3---------R4
> > | ----R2----|
> > |
> > R1
> >
> > What I'm trying to depict in the above diagram is a triangle
> > topology between
> > R2, R3, and R4. R1 hanging off of R2 outside the triangle.
> > All routers are running EIGRP on all interfaces. I create a
> > loopback of
> > 1.1.1.1/32 on R1. I then see the route travel from R1 to R2, from
> > R2 to R3
> > and
> > R4 and finally (and most confusingly) from R3 to R4 and from R4 to R3.
> > It is this last part that I am having trouble with. When R3 learns
> > the
> > route of
> > 1.1.1.1/32 from R2 and sends it to R4, shouldn't R4 NOT send that
> > same route
> > back to R3 due to split horizon???
> >
> > I show in the 'show ip eigrp
> > top all' on both R3 and R4 that this route is
> > learned from each other.
> >
> > Can
> > someone help me to better understand this?
> >
> > Thanks in advance :)
> >
> > Dave
> > Make a small loan, Make a big difference - Kiva.org
> > ________________________________
> > From: Juan <fferrer10_at_gmail.com>
> > To: Cisco
> > certification <ccielab_at_groupstudy.com>
> > Sent: Fri, January 7, 2011 1:35:34 AM
> > Subject: Test, Please ignore
> >
> > Test
> >
> >
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Received on Sat Jan 08 2011 - 14:55:03 ART