Router as a Frame Relay

Router 4 is acting a Frame Switch.

Configuration of Router 1

interface Serial0/0
 ip address 10.10.10.1 255.255.255.0
 encapsulation frame-relay
 serial restart-delay 0
 frame-relay interface-dlci 102
 frame-relay interface-dlci 103

router eigrp 1
 network 10.10.10.0 0.0.0.255
 no auto-summary


Configuration of Router 2


interface Serial0/0
 ip address 10.10.10.2 255.255.255.0
 encapsulation frame-relay
 serial restart-delay 0
 frame-relay interface-dlci 201
 frame-relay interface-dlci 203

router eigrp 1
 network 10.10.10.0 0.0.0.255
 no auto-summary


Configuration of Router3


interface Serial0/0
 ip address 10.10.10.3 255.255.255.0
 encapsulation frame-relay
 serial restart-delay 0
 frame-relay interface-dlci 301
 frame-relay interface-dlci 302


router eigrp 1
 network 10.10.10.0 0.0.0.255
 no auto-summary

Configuration of Router4 (FRAME RELAY SWITCH)


frame-relay switching       (now router will act as a frame relay switch)


interface Serial0/0
 no ip address
 encapsulation frame-relay
 serial restart-delay 0
 frame-relay intf-type dce
 frame-relay route 102 interface Serial0/1 201
 frame-relay route 103 interface Serial0/2 301
!
interface Serial0/1
 no ip address
 encapsulation frame-relay
 serial restart-delay 0
 frame-relay intf-type dce
 frame-relay route 201 interface Serial0/0 102
 frame-relay route 203 interface Serial0/2 302
!
interface Serial0/2
 no ip address
 encapsulation frame-relay
 serial restart-delay 0
 frame-relay intf-type dce
 frame-relay route 301 interface Serial0/0 103
 frame-relay route 302 interface Serial0/1 203
!

The [no] ip split-horizon command controls Split Horizon behavior for RIP; the [no] ip split-horizon eigrp asn command controls Split Horizon behavior for EIGRP.

Displaying the EIGRP Split Horizon state of an interface is an unusually difficult piece of information to find without simply displaying the configuration. By default, IOS enables EIGRP Split Horizon. To find the setting for an interface, look for the presence or absence of the no ip split-horizon eigrp command on the configuration. Also, the debug ip eigrp command output displays messages stating when prefixes are not advertised out an inter-face due to split horizon.