Frame Relay Switch - Subinterfaces

Question:

If a frame relay switch WS-C3560X-24T-L Price (Cloud) is connected to other routers with a point to point configuration using sub-interfaces, does the frame relay switch interfaces require subinterfaces to match?

Answer:

No, a Frame Relay switch does not even have subinterfaces, regardless of the end router configuration (multipoint or point-to-point). This is a sample configuration of a Frame Relay switch, it will make things a little easier to understand:

frame-relay switching

interface Serial0/0

description => To R1 - Hub router <=

encapsulation frame-relay

frame-relay intf-type dce

frame-relay route 102 interface Serial0/1 201

frame-relay route 103 interface Serial0/2 301

!

interface Serial0/1

description => To R2 - Spoke router <=

encapsulation frame-relay

frame-relay intf-type dce

frame-relay route 201 interface Serial0/0 102

!

interface Serial0/1

description => To R3 - Spoke router <=

encapsulation frame-relay

frame-relay intf-type dce

frame-relay route 301 interface Serial0/0 103

This configuration is a typical hub-and-spoke configuration where R1 has PVCs to routers R2 and R3, while routers R2 and R3 have only a single PVC towards the hub router R1. Note that regardless of how many PVCs are configured on an interface, a Frame Relay switch does not use subinterfaces.

Please feel welcome to WS-C3560X-24T-L ask further!