Cisco IOS Wide-Area Networking Configuration Guide - Free Books

Customizing Frame Relay for Your NetworkConfiguring Frame RelayStep 1CommandRouter(config)# interface typenumber.subinterface-number {multipoint |point-to-point}PurposeCreates a point-to-point or multipoint subinterface.Step 2 Router(config-subif)# encapsulation frame-relay Configures Frame Relay encapsulation on the serialinterface.For an example of configuring Frame Relay subinterfaces, see the section “Subinterface Examples” laterin this chapter.Defining Subinterface AddressingFor point-to-point subinterfaces, the destination is presumed to be known and is identified or implied inthe frame-relay interface-dlci command. For multipoint subinterfaces, the destinations can bedynamically resolved through the use of Frame Relay Inverse ARP or can be statically mapped throughthe use of the frame-relay map command.See the following sections for further information about subinterface addressing:• Addressing on Point-to-Point Subinterfaces• Addressing on Multipoint Subinterfaces• Accepting Inverse ARP for Dynamic Address Mapping on Multipoint Subinterfaces• Configuring Static Address Mapping on Multipoint SubinterfacesFor subinterface addressing examples, see the section “Static Address Mapping Examples” later in thischapter.Addressing on Point-to-Point SubinterfacesIf you specified a point-to-point subinterface in the preceding procedure, use the following command insubinterface configuration mode:CommandRouter(config-subif)# frame-relayinterface-dlci dlciPurposeAssociates the selected point-to-point subinterface with a DLCI.NoteThis command is typically used on subinterfaces; however, it can also be applied to main interfaces. Theframe-relay interface-dlci command is used to enable routing protocols on main interfaces that areconfigured to use Inverse ARP. This command is also helpful for assigning a specific class to a singlePVC on a multipoint subinterface.For an explanation of the many available options for this command, refer to the Cisco IOS Wide-AreaNetworking Command Reference.If you define a subinterface for point-to-point communication, you cannot reassign the same subinterfacenumber to be used for multipoint communication without first rebooting the router or access server.Instead, you can simply avoid using that subinterface number and use a different subinterface number.34