Configuring Frame Relay with SDM

Now that our serial connection between the Corp and R3 routers is up and running with PPP and you know how to configure PPPoE, I want to show you how easy it is to set up Frame Relay using SDM. After deleting the interface configuration through the SDM (by the way, I’m starting to get annoyed at this deleting the interface thing before I can reconfigure them!), I get to create a new serial connection.

I’ll open the Interface Wizard and choose Frame Relay for the Serial0/2/0 interface of the Corp router.

I then got the same screen I got when I configured the PPP interface. I set the static IP address and clicked Next.

In the real world, this is where I would add the LMI and DLCI information given to me from my provider.

Notice that check box at the bottom left that asks if you want to use IETF encapsulation? Remember, that means you don’t have a Cisco router on the other side of the Frame Relay cloud. After clicking Next, I got the Summary screen.

This one shows a summary of my configuration. I clicked Finish to upload it to my router. Let’s take a look at the CLI to find out what, exactly, was uploaded to my router. Notice in the following output how the IP address from the physical interface has been moved to the subinterface the SDM created—nice!

!
interface Serial0/2/0
description Connection to R3$FW_OUTSIDE$
no ip address
ip verify unicast reverse-path
ip virtual-reassembly
encapsulation frame-relay
clock rate 2000000
frame-relay lmi-type ansi
!
interface Serial0/2/0.1 point-to-point
ip address 10.1.5.1 255.255.255.0
frame-relay interface-dlci 17 CISCO
!

If I had this router connected to an ISP and the ISP were correctly configured (that can truly be a big if ), then my PVC should have come up. Just remember—I used the LMI type Cisco, meaning that my ISP would have a Cisco Frame Relay switch. This is extremely unlikely. Most of the time you would use ANSI LMI.

All right, so now let’s create a virtual private network between our Corp router and the R3 router.