EIGRP - Split Horizon

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 - 09:54:41 ART