To configure two Cisco 1841 Integrated Services Router routers using Frame Relay, follow these step-by-step instructions.
Network Topology
PC1 ---- Router1 ===== Frame Relay Cloud ===== Router2 ---- PC2
Router1 Serial0/0/0 → DLCI 100
Router2 Serial0/0/0 → DLCI 200
Example IP Addressing
| Device | Interface | IP Address | Subnet Mask |
|---|---|---|---|
| Router1 | Fa0/0 | 192.168.1.1 | 255.255.255.0 |
| Router1 | S0/0/0 | 10.1.1.1 | 255.255.255.0 |
| Router2 | Fa0/0 | 192.168.2.1 | 255.255.255.0 |
| Router2 | S0/0/0 | 10.1.1.2 | 255.255.255.0 |
STEP 1 — Connect Devices
Required
2 Cisco 1841 Routers
Serial DCE/DTE Cable
Console Cable
PCs
STEP 2 — Access Router CLI
Connect console cable and open:
PuTTY
Tera Term
HyperTerminal
Press:
Enter
STEP 3 — Configure Router1
Enter Global Configuration
enable
configure terminal
Configure FastEthernet
interface fastethernet0/0
ip address 192.168.1.1 255.255.255.0
no shutdown
exit
Configure Serial Interface for Frame Relay
interface serial0/0/0
encapsulation frame-relay
ip address 10.1.1.1 255.255.255.0
frame-relay interface-dlci 100
clock rate 64000
no shutdown
exit
Add Static Route
ip route 192.168.2.0 255.255.255.0 10.1.1.2
Save Configuration
end
write memory
STEP 4 — Configure Router2
Enter Configuration Mode
enable
configure terminal
Configure FastEthernet
interface fastethernet0/0
ip address 192.168.2.1 255.255.255.0
no shutdown
exit
Configure Serial Interface
interface serial0/0/0
encapsulation frame-relay
ip address 10.1.1.2 255.255.255.0
frame-relay interface-dlci 200
no shutdown
exit
Add Static Route
ip route 192.168.1.0 255.255.255.0 10.1.1.1
Save Configuration
end
write memory
STEP 5 — Verify Frame Relay
Check Interface Status
show ip interface brief
Interfaces should display:
up up
Verify Frame Relay
show frame-relay pvc
show frame-relay map
STEP 6 — Test Connectivity
From Router1:
ping 10.1.1.2
ping 192.168.2.1
From Router2:
ping 10.1.1.1
OPTIONAL — Configure Frame Relay Mapping
If inverse ARP does not work:
Router1
interface serial0/0/0
frame-relay map ip 10.1.1.2 100 broadcast
Router2
interface serial0/0/0
frame-relay map ip 10.1.1.1 200 broadcast
Useful Verification Commands
| Command | Purpose |
|---|---|
show running-config | View configuration |
show controllers serial 0/0/0 | Check DCE/DTE |
show frame-relay lmi | Verify LMI |
show frame-relay pvc | PVC status |
show ip route | Routing table |
Expected Result
Router1 and Router2 communicate successfully
Frame Relay PVC becomes ACTIVE
PCs can communicate across routers
Example Complete Router1 Configuration
hostname Router1
interface fastethernet0/0
ip address 192.168.1.1 255.255.255.0
no shutdown
interface serial0/0/0
encapsulation frame-relay
ip address 10.1.1.1 255.255.255.0
frame-relay interface-dlci 100
clock rate 64000
no shutdown
ip route 192.168.2.0 255.255.255.0 10.1.1.2
Example Complete Router2 Configuration
hostname Router2
interface fastethernet0/0
ip address 192.168.2.1 255.255.255.0
no shutdown
interface serial0/0/0
encapsulation frame-relay
ip address 10.1.1.2 255.255.255.0
frame-relay interface-dlci 200
no shutdown
ip route 192.168.1.0 255.255.255.0 10.1.1.1