Case Study 1—A Large Number of EIGRP Neighbors over a Frame Relay LinkBroadcast Emulation on Switched WAN (Pseudobroadcasting)Layer 2 to Layer 3 Mapping in WAN EnvironmentTroubleshooting Neighbor Map ProblemsScenario 1—Missing Broadcast Keyword on a Neighbor MapScenario 2—Wrong IP Address in the Neighbor MapScenario 3—Wrong DLCI Number in the Neighbor MapSubinterfacesPoint-to-Point and Multipoint SubinterfacesCreating, Configuring, and Removing SubinterfacesUsing Subinterfaces to Reduce Interface Output Load Due to EIGRP Hello PacketsSummary