Basics to configure a CISCO router to Share Internet

Any Cisco router you have around you say Cisco 1000, 1600, 2500, 2600, And 3600 Series Routers. Any cisco router you have the below configurations will be able to workout. These configurations will help you connect your LAN onto internet, Provide basic security to your Local Area Network (LAN) so that no other network connects if not defined in the configs. 
I will go straight to what I have around me to have this configuration done successfully.


1. Router: Cisco 1600 series.
2. ISP Addresses: [IP Address: 192.168.23.11 SubMask: 255.255.255.0 Gateway:192.168.23.1].
3. LAN Addresses: [IP Address: 10.100.10.1 SubnetMask: 255.255.255.0]
4. Console Cable.

Step 1:
-    Connect your router into power and connect your console cable (will need an RJ-45 to DB-25 adapter). Power up that router without wasting a lot of time.
-    Open up your HyperTerminal: Start -> All Programs -> Accessories ->Communications -> HyperTerminal.
-    You can name anything your “Connection Description” mine is “ictmagazine” and choose 2nd icon.

-    Press OK , Then on the next interface choose a “COM” port your console is connecting to from the router. Mine was COM3 then press OK.
-    On the next screen restore to defaults “Restore Defaults” and you should be having something similar to that below.

Then press OK. You should be in your router now.
Well I will avoid you all the boring talk and just dive straight into the really thing “configuring a router to internet”, so let us go straight to step 2.
Please note that the names and password have used those are as per on my router. You can use anything you prefer to make sure your configurations are secure and matching to your standards.

..............Step 2:  Configure Basics
Router>en
Router# config t
Router(config)# hostname ICT
ICT(config)# enable password joinict
ICT(config)# enable secret m@g@z1n3
ICT(config)# ip name-server 208.67.222.222

...............Step 3: Configuring the Line console and vty 0 4
ICT(config)# line console 0
ICT(config-line)# password g3t1n
ICT(config-line)# login
ICT(config-line)# exit

ICT(config)# line vty 0 4
ICT(config-line)# password b0b0ut
ICT(config-line)# login
ICT(config-line)# exit

................Step 4: setting up the LAN interface
ICT(config)# interface Ethernet1/0
ICT(config-if)# Description ICTMAGAZINE LAN
ICT(config-if)# ip address 10.100.10.1 255.255.255.0
ICT(config-if)# ip nat inside
ICT(config-if)# no shutdown
ICT(config-if)# exit

....................Step 5: setting up the INTERNET interface (this interface has IP Addresses provided by Internet provider –ISP)
ICT(config)# interface FastEthernet0/0
ICT(config-if)# Description Broadband Internet
ICT(config-if)# ip address 192.168.23.11 255.255.255.0
ICT(config-if)# ip nat outside
ICT(config-if)# no shutdown
ICT(config-if)# exit


....................Step 6: Configuring NAT and Routing statements.
ICT(config)# ip nat inside source list 1 interface FastEthernet0/0 overload
ICT(config)# ip route 0.0.0.0 0.0.0.0 192.168.23.1

...................Step 7: Configuring the Access-list 1 (This allows the LAN to get connection to the internet).
ICT(config)# access-list 1 permit 10.100.10.0 0.0.0.255

..................Step 8: Run show commands to confirm your configurations
ICT(config)# show interface ethernet1/0 (verify the LAN IP configuration)
ICT(config)# show interface fastethernet 0/0 (verify External/ISP IP configuration and status)
ICT(config)# Show ip route (show your routing statement if its correct)
ICT(config)# show ip nat translations (This is to confirm if your nat statements are right)
ICT(config)# show access-lists (configured access lists)

.................Step 9: Save your router configurations
ICT(config)#wr

Pheeeeeeeewwwwwwwwwww………….atlast we are done! At this point you should be in position to access internet using your cisco router.
There is a lot you can do with your cisco router. Let me know what you want to do on your cisco router. We shall be glad to help you out.

Source : http://www.yourictmagazine.com/techonology/tips-a-tricks/206-basic-to-configure-a-cisco-router-to-connect-to-internet-