I have searched on many sites about establishing a connection between a Cisco router and the internet but couldn’t find out the exact answer that I was looking for. I have a Cisco 851W with IOS 12.4 including firewall. How to connect a Cisco router to the Internet?
As your system has two Ethernet interfaces, you can easily set up the connection with these simple steps:
1. Connect the router to your PC with the help of console cable.
2. Identify your router’s interfaces i.e. the Ethernet Ports to connect the WAN device and the LAN.
3. Next, configure the IP Addresses.
4. Set up access lists: one will be applied to WAN interface and other to the LAN.
5. Configure and set up an inspection rule each for TCP/UDP/ICMP.
6. In the inbound direction, apply both the access lists and inspection rules to appropriate interfaces.
7. Set up NAT in between the internal network and the public Internet.
8. Enable interfaces, and disable STP.
9. Save and test your configuration.
