AIS AI2524 user manual Define Subinterface Addressing, Examples Basic Subinterface

Chapter 13: AI2524 Frame Relay Configuration Steps

Define Subinterface Addressing

For point-to-point subinterfaces, the destination is presumed to be known and is identified or implied in the frame-relay inter- face-dlcicommand. For multipoint subinterfaces, the destinations can be dynamically resolved through the use of Frame Relay Inverse ARP or can be statically mapped through the use of the frame- relay map command.

Addressing on Point-to-Point Subinterfaces

If you specified a point-to-point subinterface in Step 3 unde Define

Frame Relay Subinterfaces, type (in interface configuration mode):

frame-relay interface-dlci dlci [option]

If you define a subinterface for point-to-point communication, you cannot reassign the same subinterface number to be used for multi- point communication without first rebooting the router or access server. Instead, you can simply avoid using that subinterface numbe and use a different subinterface number instead.

Examples: Basic Subinterface

In this example, subinterface 1 models a point-to-point subnet and sub- interface 2 models a broadcast subnet. For emphasis, the multipoint keyword is used for serial subinterface 2, even though a subinterface is multipoint by default.

interface serial 0 encapsulation frame-relay interface serial 0.1 point-to-point ip address 10.0.1.1 255.255.255.0 frame-relay interface-dlci 42

interface serial 0.2 multipoint ip address 10.0.2.1 255.255.255.0 frame-relay map 10.0.2.2 18

Addressing on Multipoint Subinterfaces

If you specified a multipoint subinterface in Step 3 under Define Frame Relay Subinterfaces, perform the tasks in one or both of the these sections:

zAccept Inverse ARP for Dynamic Address Mapping on Multi- point Subinterfaces

zConfigure Static Address Mapping on Multipoint Subinterfaces

August 1997	Page 13-21
2524UM