Datasheet

Lab – Configuring Frame Relay and Subinterfaces
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FR# show frame-relay route
Input Intf Input Dlci Output Intf Output Dlci Status
Serial0/0/0 103 Serial0/0/1 301 inactive
Serial0/0/1 301 Serial0/0/0 103 inactive
Part 3: Configure Basic Frame Relay
In Part 3, you will configure Frame Relay on routers R1 and R3. After Frame Relay is configured, you will
enable the EIGRP routing protocol to provide end-to-end connectivity.
Step 1: Configure R1 for Frame Relay.
Inverse ARP allows distant ends of a Frame Relay link to discover each other dynamically, and provides a
dynamic method of mapping IP addresses to DLCIs. Although Inverse ARP is useful, it is not always reliable.
The best practice is to map IP addresses to DLCIs statically and disable Inverse ARP.
a. Change the encapsulation on S0/0/0 to Frame Relay.
R1(config)# interface s0/0/0
R1(config-if)# encapsulation frame-relay
b. Use the no frame-relay inverse-arp command to disable Inverse ARP.
R1(config)# interface s0/0/0
R1(config-if)# no frame-relay inverse-arp
c. Use the frame-relay map command to map an IP address to a DLCI statically. In addition to mapping an
IP to a DLCI, Cisco IOS software allows several other Layer 3 protocol addresses to be mapped. In the
following command, the broadcast keyword sends any multicast or broadcast traffic destined for this link
over the DLCI. Most routing protocols require the broadcast keyword to function properly over Frame
Relay. You can use the broadcast keyword on multiple DLCIs on the same interface. The traffic is
replicated to all PVCs.
Note: The IPv6 Frame Relay map to a global unicast address does not include the broadcast keyword.
However, the broadcast keyword is used in the mapping to the link-local address. IPv6 routing protocols
use link-local addresses for multicast routing updates; therefore, only the link-local address map requires
the broadcast keyword to forward multicast packets.
R1(config)# interface s0/0/0
R1(config-if)# frame-relay map ip 10.1.1.2 103 broadcast
R1(config-if)# frame-relay map ipv6 2001:db8:acad:b::3 103
R1(config-if)# frame-relay map ipv6 fe80::3 103 broadcast
d. For the router to ping its own interface, the DLCI must be created to map to the local interface.
R1(config)# interface s0/0/0
R1(config-if)# frame-relay map ip 10.1.1.1 103
R1(config-if)# frame-relay map ipv6 2001:db8:acad:b::1 103
e. Use the no shutdown command to activate S0/0/0.
R1(config-if)# no shutdown
Step 2: Configure R3 for Frame Relay.
R3(config)# interface s0/0/1
R3(config-if)# encapsulation frame-relay
R3(config-if)# no frame-relay inverse-arp