Cisco Router – Frame relay switch configuration (Point to Point)

This Post is for Point to Point, I will do a further post on Point to MultiPoint
So, as part of my CCIE practice lab I’ve got a frame relay cloud for testing point to point and multipoint connections.
Totally forgot how to do this (the phrase use it or loose it comes to mind!) so it took me a little while to remember it. I also mixed up my interfaces labels in GNS3 which gave me about 20mins of troubleshooting time!
Anyhoo, onto the config, we have our frame relay switch in the middle of our devices (the orange router in the diagram);
This is what were going to implement…

Firstly, we need to enable frame relay switching;
R1(config)#frame-relay switching

Next, we configure one of the interface’s to one of the spoke routers; first we set the port to encapsulate traffic with the frame-relay protocol. This is a Layer 2 (OSI Data Layer) protocol.
R1(config)#interface Serial1/0
R1(config-if)#encapsulation frame-relay

Next, we set our clock rate, this is effectively the bandwidth limit of the interface, here its 64k
R1(config-if)#clock rate 64000

Next, we disable inverse-arp, set our LMI type to ansi and set the interface as ‘dce’
R1(config-if)#no frame-relay inverse-arp
R1(config-if)#frame-relay lmi-type ansi
R1(config-if)#frame-relay intf-type dce

Finally we get to the interesting bit – we need to map our ‘local’ dlci on this interface to the egress
R1(config-if)#frame-relay route 101 interface Serial0/1 201
R1(config-if)#frame-relay route 102 interface Serial0/2 302

This is the final interface configuration;
interface Serial0/0
- no ip address
- encapsulation frame-relay
- serial restart-delay 0
- clock rate 64000
- no frame-relay inverse-arp
- frame-relay lmi-type ansi
- frame-relay intf-type dce
- frame-relay route 101 interface Serial0/1 201
- frame-relay route 102 interface Serial0/2 302

Obviously we need to do a similar configuration for the other ports;
interface Serial0/1
- no ip address
- encapsulation frame-relay
- serial restart-delay 0
- clock rate 64000
- no frame-relay inverse-arp
- frame-relay lmi-type ansi
- frame-relay intf-type dce
- frame-relay route 201 interface Serial0/0 101
- frame-relay route 203 interface Serial0/2 303
interface Serial0/2
- no ip address
- encapsulation frame-relay
- serial restart-delay 0
- clock rate 64000
- no frame-relay inverse-arp
- frame-relay lmi-type ansi
- frame-relay intf-type dce
- frame-relay route 302 interface Serial0/0 102
- frame-relay route 303 interface Serial0/1 203

Now that the frame relay switch is configured, we need to configure the 3x spoke routers;
This is what we will be configuring;

We set our primary interface to use frame-relay encapsulation, set our lmi-type to ansi and disable inverse-arp;
TOP-RTR(config)#interface Serial0/0
TOP-RTR(config-if)#no ip address
TOP-RTR(config-if)#encapsulation frame-relay
TOP-RTR(config-if)# frame-relay lmi-type ansi
TOP-RTR(config-if)#no frame-relay inverse-arp

As this is a point to point configuration, we create multiple sub-interfaces. The sub interface ID does not need to match the frame relay dlci, however i find it tidier to do so;
TOP-RTR(config)#interface Serial0/0.101 point-to-point
TOP-RTR(config-if)#ip address 203.0.113.1 255.255.255.252
TOP-RTR(config-if)#frame-relay interface-dlci 101
!
TOP-RTR(config)#interface Serial0/0.102 point-to-point
TOP-RTR(config-if)#ip address 203.0.113.5 255.255.255.252
TOP-RTR(config-if)#frame-relay interface-dlci 103

This is our final config;
TOP Router
interface Serial0/0
no ip address
encapsulation frame-relay
serial restart-delay 0
no frame-relay inverse-arp
frame-relay lmi-type ansi
!
interface Serial0/0.101 point-to-point
ip address 203.0.113.1 255.255.255.252
frame-relay interface-dlci 101
!
interface Serial0/0.102 point-to-point
ip address 203.0.113.5 255.255.255.252
frame-relay interface-dlci 102

Again we need to do this for the other 2x spoke routers;
LEFT Router
!
interface Serial0/0
no ip address
encapsulation frame-relay
serial restart-delay 0
no frame-relay inverse-arp
frame-relay lmi-type ansi
!
interface Serial0/0.201 point-to-point
ip address 203.0.113.2 255.255.255.252
frame-relay interface-dlci 201
!
interface Serial0/0.203 point-to-point
ip address 203.0.113.9 255.255.255.252
frame-relay interface-dlci 203
RIGHT Router
!
interface Serial0/0
no ip address
encapsulation frame-relay
serial restart-delay 0
no frame-relay inverse-arp
frame-relay lmi-type ansi
!
interface Serial0/0.302 point-to-point
ip address 203.0.113.6 255.255.255.252
frame-relay interface-dlci 302
!
interface Serial0/0.303 point-to-point
ip address 203.0.113.10 255.255.255.252
frame-relay interface-dlci 303

And there you have it, frame relay network ready to go!
TOP-RTR#show frame-relay map
Serial0/0.101 (up): point-to-point dlci, dlci 101(0x65,0x1850), broadcast
status defined, active
Serial0/0.102 (up): point-to-point dlci, dlci 102(0x67,0x1870), broadcast
status defined, active
TOP-RTR#show frame-relay pvc summary
Frame-Relay VC Summary
Active Inactive Deleted Static
Local 2 0 0 0
Switched 0 0 0 0
Unused 0 0 0 0

FW-SWITCH#show frame-relay pvc summary
Frame-Relay VC Summary
Active Inactive Deleted Static
Local 0 0 0 0
Switched 6 0 0 0
Unused 0 0 0 0