Image of Jeremy L. Gaddis, CCNA, CCNP (and Cortney, in case you were wondering)

Frame-Relay Switch Configuration

by Jeremy L. Gaddis

Configuring a frame-relay switch isn’t something you’ll have to do in order to earn the Cisco CCNA certification, but we will need one in order to complete the lab exercises that use frame-relay.

In the Free CCNA Labs Topology, we’ll only be using five frame-relay connections (one to each router), each of which operates at 128 kbps.

If you’re have a home Cisco lab, you can configure a real router as a frame-relay switch or a virtual router running under Cisco IOU or Dynamips/GNS3. There is no difference in configuration (other than perhaps the correct interface names). What is key, however, is that we get the interface to DLCI mappings correct or we’ll run into some interesting issues when we begin to configure frame-relay connections.

NOTE: If you’re just getting started in Cisco and none of this makes sense to you yet, don’t worry. We’ll take about frame-relay in great detail later and you’ll become very familiar with it. If you work through the labs in order (or you’re enrolled in Cisco Academy), you won’t need a frame-relay switch until towards the end.

The interface to DLCI mappings for the frame-relay switch are listed on the Free CCNA Labs topology page.

With these mappings lined out, we can begin configuring our frame-relay switch to properly direct the frames out the correct interfaces. Assuming that you’re using following along with the topology, the frame-relay switch configuration should look like this:

interface s0/0
 description CONNECTED TO CHICAGO S1/0
 encapsulation frame-relay
 clock rate 128000
 frame-relay intf-type dce
 frame-relay route 401 interface s1/3 104
 frame-relay route 402 interface s0/2 204
 frame-relay route 403 interface s0/3 304
 frame-relay route 405 interface s0/1 504

interface s0/1
 description CONNECTED TO NEWYORK S1/0
 encapsulation frame-relay
 clock rate 128000
 frame-relay intf-type dce
 frame-relay route 501 int s1/3 105
 frame-relay route 502 int s0/2 205
 frame-relay route 503 int s0/3 305
 frame-relay route 504 int s0/0 405

interface s0/2
 description CONNECTED TO DALLAS S1/0
 encapsulation frame-relay
 clock rate 128000
 frame-relay intf-type dce
 frame-relay route 201 int s1/3 102
 frame-relay route 203 int s0/3 302
 frame-relay route 204 int s0/0 402
 frame-relay route 205 int s0/1 502

interface s0/3
 description CONNECTED TO MIAMI S1/0
 encapsulation frame-relay
 clock rate 128000
 frame-relay intf-type dce
 frame-relay route 301 int s1/3 103
 frame-relay route 302 int s0/2 203
 frame-relay route 304 int s0/0 403
 frame-relay route 305 int s0/1 503

interface s1/3
 description CONNECTED TO PHOENIX S1/0
 encapsulation frame-relay
 clock rate 128000
 frame-relay intf-type dce
 frame-relay route 102 int s0/2 201
 frame-relay route 103 int s1/0 301
 frame-relay route 104 int s0/0 401
 frame-relay route 105 int s0/1 501

If you follow my topology and use the above configuration, you should have full-mesh connectivity between all routers via frame-relay virtual circuits.