I have a Hub-and-spokes Frame Relay network. 3 routers with 3 loopbacks.
R1 is the hub. R2 and R3 are spokes.
Each router advertises his loopback and the directly connected network. But it seems that each spoke does not see the other spoke's loopback (as part of EIGRP advertisements).
Is it an issue of Split Horizon with EIGRP? how to solve it?
Your post is not clear whether the Frame Relay is configured as multipoint at the hub or as a combination of point to point subinterfaces. From the symptoms I assume that it is multipoint. It is the default behavior of EIGRP to enforce split horizon in multipoint implementations of EIGRP. To fix this you should turn off split horizon for EIGRP.