From: NET HE (he_net@hotmail.com)
Date: Tue Aug 14 2007 - 22:34:03 ART
Hi there,
Today I tried a couple of configurations to pratise split-horizon rule while
redistributiing between routing protocols, results are as follow. It would
be very appreciated if someone can explain me why?
(IOS 12.4)
Topology:
Router1 has loop0 (10.0.0.1 255.255.255.255) and fa0/0 (172.16.1.1
255.255.255.0)
Router2 has fa0/0 (172.16.1.2 255.255.255.0)
Router3 has loop0 (10.0.0.3 255.255.255.255) and fa0/0 (172.16.1.3
255.255.255.0)
All fa0/0s are connected to an ethernet segment.
Case 1:
Router1 configuration
Router eigrp 100
no auto
network 172.16.0.0
network 10.0.0.0
Router2 configuration
Router eigrp 100
no auto
network 172.16.0.0
default-metric 10000 10 1 255 1500
redistribute eigrp 10
Router eigrp 10
no auto
network 172.16.0.0
default-metric 10000 10 1 255 1500
redistribute eigrp 100
Router3 configuration
Router eigrp 10
no auto
network 172.16.0.0
network 10.0.0.0
I don't have to disable split-horizon at all at fa0/0 on router 2, router1
sees 10.0.0.3 via 172.16.1.2 (next-hop) and router1 sees 10.0.0.1 via
172.16.1.2 (next-hop).
But when eigrp 10 is replaced by RIP, and redistribution happens betwen
eigrp 100 and RIP, I have to disable split-horizon @Route2 for RIP so that
Router3 can see 10.0.0.1. Here are questions:
1)When the distribution happens between 2 different eigrp AS, @ Router1
route 10.0.0.3 and @Router2 route 10.0.0.1 both point to 172.16.1.2 as
next-hop address, but When the distribution happens between eigrp and RIP,
@Router1 route 10.0.0.3 which is redistributed from RIP is via 172.16.1.2
(next-hop) but @ Router3 route 10.0.0.1 which is redistributed from eigrp
100 is via 172.1.1.1 (next-hop), why are they different in terms of
next-hop?
2)What's the split-horizon rule while doing redistribution
Thanks.
This archive was generated by hypermail 2.1.4 : Sat Sep 01 2007 - 11:32:11 ART