Configuring the WAN Interface
                                            This procedure describes how to configure the WAN interface and uses Gigabit Ethernet as an example. If you are using a different WAN interface, refer to the CLI Reference Guide.
                                            
                                                Before configuring the WAN interface, make sure that you have all the required information from your Internet Telephony Service Provider (ITSP)
                                             
                                            
                                                
                                                
                                                
                                                
                                                    |  | ➢ | To configure a WAN IP address: | 
                                            
                                            
                                                
                                                
                                                
                                                
                                                    |  | 1. | Connect the WAN port to the WAN network. For information on cabling the WAN port, refer to the Hardware Installation Manual. | 
                                            
                                            
                                                
                                                
                                                
                                                
                                                    |  | 2. | Establish serial communication with the device. | 
                                            
                                            
                                                
                                                
                                                
                                                
                                                    |  | 3. | At the prompt, type the following command to access the router configuration mode: | 
                                            
# configure data
                                            
                                                
                                                
                                                
                                                
                                                    |  | 4. | Access the WAN interface: | 
                                            
(config-data)# interface GigabitEthernet 0/0
                                            
                                                
                                                
                                                
                                                
                                                    |  | 5. | Configure the IP address and subnet mask: | 
                                            
(config-if-GE 0/0)# ip address 100.33.2.105  255.255.255.0
                                            
                                                
                                                
                                                
                                                
                                                    |  | 6. | Enable the WAN interface: | 
                                            
(config-if-GE 0/0)# no shutdown
                                            (config-if-GE 0/0)# exit
                                            
                                                
                                                
                                                
                                                
                                                    |  | 8. | Configure the default route: | 
                                            
(config-data)# ip route 0.0.0.0 0.0.0.0 100.33.2.106 GigabitEthernet 0/0
                                            
                                                
                                                
                                                
                                                
                                                    |  | 9. | Exit the router configuration mode: | 
                                            
(config-data)# exit
                                            
                                                
                                                
                                                
                                                
                                                    |  | 10. | Save the configuration to flash: | 
                                            
# write