Command
Frame-Relay Inverse-Arp
Use
This command enables frame-relay inverse-arp. Frame-relay uses inverse-map to dynamically learn remote IP addresses and its local DLCIs.
Syntax
Router(config-if)#frame-relay inverse-arp
OR
Router(config-if)#frame-relay inverse-arp ip <dlci>
Example
In this example we will configure R4 to use frame-relay.
R4(config)#int s0/0 R4(config-if)#encapsulation frame-relay R4(config-if)#ip add 10.4.4.4 255.255.255.0 R4(config-if)#no shut
Next, we will configure R1 to use frame-relay.
R1(config)#int s1/0 R1(config-if)#encapsulation frame-relay R1(config-if)#ip add 10.4.4.1 255.255.255.0 R1(config-if)#no shut
After, we do the same to R3.
R3(config)#int s1/0 R3(config-if)#encapsulation frame R3(config-if)#encapsulation frame-relay R3(config-if)#ip add 10.4.4.3 255.255.255.0 R3(config-if)#no shut
Now we use show frame-relay mapping to verify that R4 has learned about the other links via inverse-arp. We also check to see that we can ping.
R4(config-if)#do sh frame map Serial0/0 (up): ip 10.4.4.1 dlci 401(0x191,0x6410), dynamic, broadcast,, status defined, active Serial0/0 (up): ip 10.4.4.3 dlci 403(0x193,0x6430), dynamic, broadcast,, status defined, active R4(config-if)#do ping 10.4.4.4 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 10.4.4.4, timeout is 2 seconds: .. Success rate is 0 percent (0/2) R4(config-if)#do ping 10.4.4.1 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 10.4.4.1, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 8/32/84 ms R4(config-if)#do ping 10.4.4.3 Type escape sequence to abort. Sending 5, 100-byte ICMP Echos to 10.4.4.3, timeout is 2 seconds: !!!!! Success rate is 100 percent (5/5), round-trip min/avg/max = 8/37/68 ms