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EIGRP routes received from a neighbor on a point-to-multipoint interface are not propagated to another neighbor on the same interaface

Core Issue

Split horizon prohibits a router from advertising a route through an interface that the router itself is using to reach the destination.


Issue the no ip split-horizon eigrp interface command to disable split horizon.

These facts are important when using split horizon:

  • Split horizon behavior is turned on by default.
  • Changing the Enhanced Interior Gateway Routing Protocol (EIGRP) split horizon setting on an interface 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.
  • EIGRP's split horizon behavior is not controlled or influenced by issuing the ip split-horizon command.

For more information, refer to the Split Horizon and Poison Reverse section of Enhanced Interior Gateway Routing Protocol.

How are Neighbors Connected

Connected via ATM

Connected via Frame Relay

show ip eigrp neighbors

Neighbor exists in neighbor table