Hi,
I assume that you have set up a hub-and-spoke scenario where Frame Relay PVCs are established only for R1/R2 and R1/R3, but there is no PVC for R2/R3.
In this case, you need to modify the configuration on R2 and R3. Both these routers believe that they are in the same IP network, and therefore they attempt to reach each other directly - but this is not possible because there is no direct PVC between them.
The solution is to add a static IP/DLCI mapping on R2 to say that in order to reach R3's address, R2 has to send the packet on the DLCI 301 - unknowingly to R1. R1 is able to talk to both R2 and R3, and it will forward the packet to R3. The same has to be configured on R3 for R2's IP address.
On R2, configure this:
interface Serial1/0
frame-relay map ip 192.168.1.103 201
On R3, configure this:
interface Serial1/0
frame-relay map ip 192.168.1.102 301
Best regards,
Peter
