Dans cette exemple une liaison de type point à point FrameRelay est configuré entre R2<->R1, et R3<->R1 , de la façon suivante
R1
interface Serial0/0.100 multipoint
ip address 10.1.1.1 255.255.255.0
frame-relay map ip 10.1.1.2 102 broadcast
frame-relay map ip 10.1.1.3 103 broadcas
R2
interface Serial0/0
ip address 10.1.1.2 255.255.255.0
encapsulation frame-relay
frame-relay map ip 10.1.1.1 201
frame-relay map ip 10.1.1.3 201
no frame-relay inverse-arp
R3
interface Serial1/0
ip address 10.1.1.3 255.255.255.0
encapsulation frame-relay
frame-relay map ip 10.1.1.1 301
frame-relay map ip 10.1.1.2 301
no frame-relay inverse-arp
Une interface loopback est configurée sur chaque routeur
Configuration de RIP v2
Configuration classique, et très simple, sur chaque routeur
R1#conf t
R1(config)#router rip
R1(config-router)#version 2
R1(config-router)#no auto-summary
R1(config-router)#network 10.0.0.0
R1(config-router)#network 1.0.0.0
R2#conf t
R2(config)#router rip
R2(config-router)#version 2
R2(config-router)#no auto-summary
R2(config-router)#network 10.0.0.0
R2(config-router)#network 2.0.0.0
R3#conf t R3(config)#router rip R3(config-router)#version 2 R3(config-router)#no auto-summary R3(config-router)#network 10.0.0.0 R3(config-router)#network 3.0.0.0
Vérifications :
R1#sho ip route rip
R 2.0.0.0/8 [120/1] via 10.1.1.2, 00:00:21, Serial0/0.100
R 3.0.0.0/8 [120/1] via 10.1.1.3, 00:00:09, Serial0/0.100
R2#show ip route rip
R 1.0.0.0/8 [120/1] via 10.1.1.1, 00:00:19, Serial0/0
R3#show ip route rip
R 1.0.0.0/8 [120/1] via 10.1.1.1, 00:00:08, Serial1/0
De part la nature de cette topologie « point à point », les routeurs R2 et R2 ne reçoivent pas correctement les informations de routage propagés par RIP
Raison du dysfonctionnement : SPLIT HORIZON est activé sur le routeur R1
R1#show ip interface s0/0.100 Serial0/0.100 is up, line protocol is up Internet address is 10.1.1.1/24 Broadcast address is 255.255.255.255 Address determined by non-volatile memory MTU is 1500 bytes Helper address is not set Directed broadcast forwarding is disabled Multicast reserved groups joined: 224.0.0.9 Outgoing access list is not set Inbound access list is not set Proxy ARP is enabled Local Proxy ARP is disabled Security level is default Split horizon is enabled ICMP redirects are always sent ICMP unreachables are always sent ICMP mask replies are never sent IP fast switching is enabled IP fast switching on the same interface is enabled IP Flow switching is disabled IP CEF switching is enabled IP CEF Fast switching turbo vector IP multicast fast switching is enabled IP multicast distributed fast switching is disabled IP route-cache flags are Fast, CEF Router Discovery is disabled IP output packet accounting is disabled IP access violation accounting is disabled TCP/IP header compression is disabled RTP/IP header compression is disabled Policy routing is disabled Network address translation is disabled BGP Policy Mapping is disabled
Correction : désactivation de « split horizon » sur R1
R1(config)#int s0/0.100 R1(config-subif)#no ip split-horizon
Vérifications :
R1#show ip interface s0/0.100 | inc Spli Split horizon is disabled R2#show ip route rip R 1.0.0.0/8 [120/1] via 10.1.1.1, 00:00:09, Serial0/0 R 3.0.0.0/8 [120/2] via 10.1.1.3, 00:00:09, Serial0/0
Attention : R1 et R2 doivent pouvoir s’atteindre mutuellement (via R1) ,
il est donc nécessaire de faire évoluer la configuration :
R2#conf t R2(config)#int s0/0 R2(config-if)#frame-relay map ip 10.1.1.3 201
R3#conf t R3(config)#int s1/0 R3(config-if)#frame-relay map ip 10.1.1.2 301