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266 Chapter 9: Frame Relay Connection Controlling Traffic Flow
Example 9-3 details the same basic configuration. The difference is that the interfaces were
created as multipoint interfaces. In other words, each subinterface is capable of connecting to
more than one remote location. This was not the case in the previous example.
Note in Example 9-3 that the command defining the circuit has changed. In addition, although
Example 9-2 specified the DLCI and nothing else, Example 9-3 created a static mapping that
associated the next-hop IP address with the local DLCI that had been created by the telco. The
frame-relay map command is the same as for other protocols. The command structure for
frame-relay map is
Router(config-if)#frame-relay map protocol protocol-address dlci [broadcast][ietf
| cisco]
Protocols supported in the frame-relay map command include IP, IPX, AppleTalk, CLNS,
DECnet, XNS, and Vines, to name just a few. The protocol-address in the command is the next
hop logical address for the router on the remote end of the connection. The dlci argument
represents the local DLCI, not that of the remote end. You should always map the local DLCI
to the next-hop address.
In the frame-relay map command, the broadcast keyword specifies that routing updates
traverse the network through this circuit. The final option in the command specifies which
Frame Relay implementation to utilize in communications with the remote router. When
communicating with a Cisco device on the remote side, the default value (cisco) can be utilized.
However, when communicating with non-Cisco gear on the remote end, it can be necessary to
specify that the IETF implementation of Frame Relay be used.
Verifying Frame Relay Configuration
The most useful method of verifying configurations is through the use of the show and debug
commands. The examples in the following subsections show sample command output.
Example 9-3
Frame Relay Subinterface Configuration (Multipoint)
RouterA(config)#interface serial 0
RouterA(config-if)#encapsulation frame-relay
RouterA(config-if)#interface serial 0.1 multipoint
RouterA(config-subif)#ip address 10.1.1.1 255.255.255.0
RouterA(config-subif)#frame-relay map ip 10.1.1.2 16 broadcast
RouterA(config-subif)#interface serial 0.2 multipoint
RouterA(config-subif)#ip address 10.1.2.1 255.255.255.0
RouterA(config-subif)#frame-relay map ip 10.1.2.2 17 broadcast
RouterA(config-subif)#interface serial 0.3 multipoint
RouterA(config-subif)#ip address 10.1.3.1 255.255.255.0
RouterA(config-subif)#frame-relay map ip 10.1.3.2 18 broadcast