How to configure the cisco router WAN and LAN interface with internet access

Network connection diagram of below configuration

 

Interface IP Configuration:

Step: 1

Login into the router with global configuration mode

Router(config)#

Step: 2

Here I’m going to configure WAN interface of the router with ISP public IP address.

WAN IP           :  192.168.1.200

WAN Subnet  :  255.255.255.0

GATEWAY      :  192.168.1.1

WAN Interface Name :  FastEthernet0/0

Router(config)#interface FastEthernet 0/0

Router(config-if)#ip address 192.168.1.200 255.255.255.0

Router(config-if)#no shutdown

Router(config-if)#exit

 

Step: 3

Now I’m going to configure the LAN interface of the router

LAN IP           :  10.10.10 1

WAN Subnet  :  255.255.255.0

LAN Interface Name :  FastEthernet0/0

Router(config)#interface gigabitEthernet 1/0

Router(config-if)#ip address 10.10.10.1 255.255.255.0

Router(config-if)#no shutdown

Router(config-if)#exit

NAT Configuration for Internet access from WAN interface to LAN interface:

Step 4:

Enable outside NAT into the WAN interface(FastEthernet 0/0) of the  router

Router(config)#interface fastethernet 0/0

Router(config-if)#ip nat outside

Router(config-if)#exit

Step 5:

Enable inside NAT into the LAN interface(GigabitEthernet 1/0) of the router.

Router(config)#interface Gigabitethernet 1/0

Router(config-if)#ip nat inside

Create an access list for allowing LAN interface IP to WAN interface:

Step 6:

create an access list for LAN IP subnet of the router (10.10.10.0/24)

Router(config)#access-list 100 permit ip 10.10.10.0 0.0.0.255 any

Router(config)#ip nat inside source list 100 interface fastEthernet 0/0

Note:

100 is the access list

Final step creating a default route for the router:

Step 7:

create a default route for accessing the internet

Router(config)#ip route 0.0.0.0 0.0.0.0 192.168.1.1

Note:

192.168.1.1 this it is the gateway of ISP

Step 8 :

Check the internet connectivity in the router

Router#ping 8.8.8.8

the same test you check in the PC( before that configure static IP address into PC Local area connection interface due to DHCP server is not enabled in the router)

Please let me know if you have any doubts.