EIGRP Lab Trouble

buemae808

I'm trying to do an EIGRP lab with three routers and frame relay. I'm setting up the hub (R1) and spoke (R2, R3) topology using R1, R2, R3 serial 0/0/0 interfaces. I can't get R2 and R3 to see each others loopbacks but I can ping each other's serial interfaces. Am I leaving something out?

R1#sh run
Building configuration...

Current configuration : 1113 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname R1
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
ip cef
!
!
!
!
no ip domain lookup
ip auth-proxy max-nodata-conns 3
ip admission max-nodata-conns 3
!
!
!
!
!
!
!
!
!
interface Loopback0
ip address 1.1.1.1 255.255.255.255
!
interface FastEthernet0/0
no ip address
shutdown
duplex auto
speed auto
!
interface FastEthernet0/1
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/0/0
ip address 172.12.123.1 255.255.255.0
encapsulation frame-relay
frame-relay map ip 172.12.123.2 122 broadcast
frame-relay map ip 172.12.123.3 123 broadcast
no frame-relay inverse-arp
!
interface Serial0/1/0
no ip address
shutdown
clock rate 2000000
!
router eigrp 1
network 1.1.1.1 0.0.0.0
network 172.12.123.0 0.0.0.255
auto-summary
!
ip forward-protocol nd
!
!
no ip http server
no ip http secure-server
!
!
!
!
!
control-plane
!
!
!
line con 0
exec-timeout 0 0
logging synchronous
line aux 0
line vty 0 4
login
!
scheduler allocate 20000 1000
end

---

R2#sh run
Building configuration...

Current configuration : 1075 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname R2
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
ip cef
!
!
!
!
no ip domain lookup
ip auth-proxy max-nodata-conns 3
ip admission max-nodata-conns 3
!
!
!
!
!
!
!
!
!
interface Loopback0
ip address 2.2.2.2 255.255.255.255
!
interface FastEthernet0/0
no ip address
shutdown
duplex auto
speed auto
!
interface FastEthernet0/1
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/0/0
ip address 172.12.123.2 255.255.255.0
encapsulation frame-relay
frame-relay map ip 172.12.123.1 221 broadcast
frame-relay map ip 172.12.123.3 221
!
interface Serial0/1/0
no ip address
shutdown
clock rate 2000000
!
router eigrp 1
network 2.2.2.2 0.0.0.0
network 172.12.123.0 0.0.0.255
auto-summary
!
ip forward-protocol nd
!
!
no ip http server
no ip http secure-server
!
!
!
!
!
control-plane
!
!
!
line con 0
exec-timeout 0 0
logging synchronous
line aux 0
line vty 0 4
login
!
scheduler allocate 20000 1000
end

---

R3#sh run
Building configuration...

Current configuration : 1103 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname R3
!
boot-start-marker
boot-end-marker
!
!
no aaa new-model
ip cef
!
!
!
!
no ip domain lookup
ip auth-proxy max-nodata-conns 3
ip admission max-nodata-conns 3
!
!
!
!
!
!
!
!
!
interface Loopback0
ip address 3.3.3.3 255.255.255.255
!
interface FastEthernet0/0
no ip address
shutdown
duplex auto
speed auto
!
interface FastEthernet0/1
no ip address
shutdown
duplex auto
speed auto
!
interface Serial0/0/0
ip address 172.12.123.3 255.255.255.0
encapsulation frame-relay
frame-relay map ip 172.12.123.1 321 broadcast
frame-relay map ip 172.12.123.2 321
no frame-relay inverse-arp
!
interface Serial0/1/0
no ip address
shutdown
clock rate 2000000
!
router eigrp 1
network 3.3.3.3 0.0.0.0
network 172.12.123.0 0.0.0.255
auto-summary
!
ip forward-protocol nd
!
!
no ip http server
no ip http secure-server
!
!
!
!
!
control-plane
!
!
!
line con 0
exec-timeout 0 0
logging synchronous
line aux 0
line vty 0 4
login
!
scheduler allocate 20000 1000
end

Plazma

the 1st thing i would suggest is turn off auto-summary via no auto-summary (this is IMHO an annoying feature set by default)

buemae808

Q. Why are routes received from one neighbor on a point-to-multipoint interface that runs EIGRP not propagated to another neighbor on the same point-to-multipoint interface?


A. The split horizon rule prohibits a router from advertising a route through an interface that the router itself uses to reach the destination. In order to disable the split horizon behavior, use the no ip split-horizon eigrp as-number interface command. Some important points to remember about EIGRP split horizon are:

* Split horizon behavior is turned on by default.
* When you change the EIGRP split horizon setting on an interface, it resets all adjacencies with EIGRP neighbors reachable over that interface.
* Split horizon should only be disabled on a hub site in a hub-and-spoke network.
* Disabling split horizon on the spokes radically increases EIGRP memory consumption on the hub router, as well as the amount of traffic generated on the spoke routers.
* The EIGRP split horizon behavior is not controlled or influenced by the ip split-horizon command.

kpjungle

buemae808 wrote:

Q. Why are routes received from one neighbor on a point-to-multipoint interface that runs EIGRP not propagated to another neighbor on the same point-to-multipoint interface?


A. The split horizon rule prohibits a router from advertising a route through an interface that the router itself uses to reach the destination. In order to disable the split horizon behavior, use the no ip split-horizon eigrp as-number interface command. Some important points to remember about EIGRP split horizon are:

* Split horizon behavior is turned on by default.
* When you change the EIGRP split horizon setting on an interface, it resets all adjacencies with EIGRP neighbors reachable over that interface.
* Split horizon should only be disabled on a hub site in a hub-and-spoke network.
* Disabling split horizon on the spokes radically increases EIGRP memory consumption on the hub router, as well as the amount of traffic generated on the spoke routers.
* The EIGRP split horizon behavior is not controlled or influenced by the ip split-horizon command.

Did you fix it using subinterfaces (point to point)?

buemae808

Someone told me to try using the "no ip split-horizon eigrp 1" command on the serial interface of the hub router which worked

nicklauscombs

buemae808 wrote:

Someone told me to try using the "no ip split-horizon eigrp 1" command on the serial interface of the hub router which worked

yes, this is what was causing your issues