Router A: Router-A(config)# int so/o Router-A(config-if)# ip address 192.168.1.1 255.255.255.248 Router B: Router-B(config)# int so/o Router-B(config-if)# ip address 192.168.1.2 255.255.255.248 Configuring Frame Relay Router C: Router-C(config)# int s0/0 Router-C(config-if)# ip address 192.168.1.3 255.255.255.248 Performing these steps gives you a live frame-relay network, which you can test as follows: Router-A# ping 192.168.1.2 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 192.168.1.2, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 56/57/60 ms Router-A# ping 192.168.1.3 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 192.168.1.3, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 56/57/60 ms When there were only two nodes on the network, the routers were each able to determine the IP address of the far side by nature of the subnet mask. That's not the case here because there are more than two nodes. When the subnet mask is other than 255.255.255.252, the routers will use Inverse ARP to determine what IP address belongs to what DLCI. Beware of Inverse ARP on complex frame-relay networks. Inverse ARP will discover all PVCs and their IP addresses, if they exist. This can cause links that you may not expect or want to come online. Inverse ARP can be disabled with the no frame-relay inverse-arp command. A better option for IP address-to-DLCI mappings is mapping them by hand. This is done with the frame-relay map interface command: Router-A(config-if)# frame-relay map ip 192.168.1.2 102 broadcast Router-A(config-if)# frame-relay map ip 192.168.1.3 103 broadcast A mapping determined by Inverse ARP is considered a dynamic map, while a config- ured map is considered a static map. Remember that each router only sees its own side of the PVC, SO you are mapping the remote IP address to the local DLCI. Think of the local DLCI as pointing to the remote router. Take a look at the commands for Router B and Router C