A(config-if)# ip address 192.168.1.1 255.255.255.248 Router B: Chapter 23: Frame Relay Router-B(config)#int so/o Router-B(config-if)# ip address 192.168.1.2 255.255.255.248 Router C: Router-C(config)#int so/o 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 deter- mine 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 which IP address belongs to which 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 unexpected or unwanted links to come online. Inverse ARP can be dis- abled with the no frame-relay inverse-arp command. A better option for IP address-to-DLCI mappings is mapping them by hand, which you do with the frame-relay map interface command: Router-A(config-if)#frame-relay map ip 192.168.1.2 102 broadcast louter-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 configured 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, and you'll see what I mean: Router B: outer-B(config-if)#f