IEWB vol.1 - RIP and IP Split Horizon Lab

From: Dino Picinich (dino.picinich@gmail.com)
Date: Wed Mar 12 2008 - 09:34:55 ARST


Hi - Strange problem that I can't seem to grasp an understanding on. It's a
simple frame relay hub and spoke topology with R1 as the hub w/ multipoint
interface and R4 and R5 as the spokes on main interface. The lab is just
showing the functionality of split horizon in this environment when running
RIP over it. The strange thing is if I ping the LAN interfaces from spoke
to spoke specifying the source as f0/0, I get 100%. If I ping and do not
specify the source (in this case it will default to S1/0) I only get 50%
success rate. An ICMP debug from R4 (source in this case pinging
destination R5 f0/0), reveals the following:

ICMP: redirect rcvd from 10.0.0.1- for 5.0.0.5 use gw 10.0.0.5

I confirmed there is no active frame circuit between R4 and R5 and confirmed
the path it takes within the network:

Rack1R4#trace 5.0.0.5

Type escape sequence to abort.

Tracing the route to 5.0.0.5

  1 10.0.0.1 4 msec 8 msec 4 msec

  2 10.0.0.5 8 msec * 20 msec

Rack1R4#

I disabled redirects on the multipoint interface of R1 but get the same 50%
success rate. I did a passive-interface on all of my f0/0 interfaces but to
no avail. Any help over this hump would be greatly appreciated.

Below are the configs from the three routers:

*******************R1******************

Rack1R1#sh run

Building configuration...

Current configuration : 1413 bytes

!

version 12.4

no service timestamps debug uptime

no service timestamps log uptime

no service password-encryption

!

hostname Rack1R1

!

boot-start-marker

boot-end-marker

!

enable password cisco

!

no aaa new-model

memory-size iomem 5

no ip cef

!

no ip domain lookup

!

interface FastEthernet0/0

 ip address 1.0.0.1 255.0.0.0

speed 100

 full-duplex

!

interface FastEthernet0/1

 no ip address

 shutdown

 speed 100

 full-duplex

!

interface Serial1/0

 no ip address

 no ip redirects

 encapsulation frame-relay

 no ip route-cache

 serial restart-delay 0

 no frame-relay inverse-arp

!

interface Serial1/0.1 multipoint

 ip address 10.0.0.1 255.0.0.0

 no ip redirects

 no ip route-cache

 no ip split-horizon

 frame-relay map ip 10.0.0.4 104 broadcast

 frame-relay map ip 10.0.0.5 105 broadcast

!

interface Serial1/1

 no ip address

 shutdown

 serial restart-delay 0

!

interface Serial1/2

 no ip address

 shutdown

 serial restart-delay 0

!

interface Serial1/3

 no ip address

 shutdown

 serial restart-delay 0

!

router rip

 passive-interface FastEthernet0/0

 network 1.0.0.0

 network 10.0.0.0

!

ip forward-protocol nd

!

!

no ip http server

no ip http secure-server

!

control-plane

!

line con 0

 exec-timeout 0 0

 privilege level 15

 logging synchronous

line aux 0

 exec-timeout 0 0

 privilege level 15

line vty 0 4

 password cisco

 login

!

***************R4**********************

Rack1R4#sh run

Building configuration...

Current configuration : 1257 bytes

!

version 12.4

no service timestamps debug uptime

no service timestamps log uptime

no service password-encryption

!

hostname Rack1R4

!

boot-start-marker

boot-end-marker

!

enable password cisco

!

no aaa new-model

memory-size iomem 5

ip cef

!

no ip domain lookup

!

interface FastEthernet0/0

 ip address 4.0.0.4 255.0.0.0

 speed 100

 full-duplex

!

interface FastEthernet0/1

 no ip address

 shutdown

 speed 100

 full-duplex

!

interface Serial1/0

 ip address 10.0.0.4 255.0.0.0

 encapsulation frame-relay

 serial restart-delay 0

 frame-relay map ip 10.0.0.1 401 broadcast

 frame-relay map ip 10.0.0.5 401

 no frame-relay inverse-arp

!

interface Serial1/1

 no ip address

 shutdown

 serial restart-delay 0

!

interface Serial1/2

no ip address

 shutdown

 serial restart-delay 0

!

interface Serial1/3

 no ip address

 shutdown

 serial restart-delay 0

!

router rip

 passive-interface FastEthernet0/0

 network 4.0.0.0

 network 10.0.0.0

!

ip forward-protocol nd

!

no ip http server

no ip http secure-server

!

control-plane

!

line con 0

 exec-timeout 0 0

 privilege level 15

 logging synchronous

line aux 0

 exec-timeout 0 0

 privilege level 15

line vty 0 4

 password cisco

 login

!

end

******************R5******************

Rack1R5#sh run

Building configuration...

Current configuration : 1265 bytes

!

version 12.4

service timestamps debug datetime msec

service timestamps log datetime msec

no service password-encryption

!

hostname Rack1R5

!

boot-start-marker

boot-end-marker

!

enable password cisco

!

no aaa new-model

memory-size iomem 5

ip cef

!

no ip domain lookup

!

interface FastEthernet0/0

 ip address 5.0.0.5 255.0.0.0

 speed 100

 full-duplex

!

interface FastEthernet0/1

 no ip address

 shutdown

 speed 100

 full-duplex

!

interface Serial1/0

 ip address 10.0.0.5 255.0.0.0

 encapsulation frame-relay

 serial restart-delay 0

 frame-relay map ip 10.0.0.1 501 broadcast

 frame-relay map ip 10.0.0.4 501

 no frame-relay inverse-arp

!

interface Serial1/1

 no ip address

 shutdown

 serial restart-delay 0

!

interface Serial1/2

 no ip address

shutdown

 serial restart-delay 0

!

interface Serial1/3

 no ip address

 shutdown

 serial restart-delay 0

!

router rip

 passive-interface FastEthernet0/0

 network 5.0.0.0

 network 10.0.0.0

!

ip forward-protocol nd

!

no ip http server

no ip http secure-server

!

control-plane

!

line con 0

 exec-timeout 0 0

 privilege level 15

 logging synchronous

line aux 0

 exec-timeout 0 0

 privilege level 15

line vty 0 4

 password cisco

 login

!

end



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