EIGRP and NAT

Experts and all other who want to be experts :)
I have one issue with task that includes EIGRP and NAT:

           Lo0
             |
          nat IN
             |
nat IN---R5 (F0/0)----NAT OUT--------14.7.225.0/24----------BB2-----Lo0
             |
          nat IN
             |

Scenario is above. Task is to solve EIGRP neighbors flapping between
R5 and BB2.
R5 is doing NAT overload:

ip nat inside source list 122 interface FastEthernet0/0 overload
!
access-list 122 permit ip any any
!

EIGRP adjacency between R5 and BB2 is flapping. Solution is to exclude
EIGRP traffic from NAT on R5:

access-list 122 deny eigrp any any
access-list 122 permit ip any any

After that adjacency is UP, routes are exchanged and everything is
nice. And here comes my question:
Why configured NAT was problem for EIGRP since R5 and BB2 are directly
connected on the same segment, so what is good explanation for
flapping? Why R5 and BB2 couldn't established EIGRP adjecency on
directly connected segment?

Vielen Dank !!

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Received on Thu Apr 22 2010 - 16:20:06 ART