Securing the Network Using Cisco Routers
It is imperative that the networks be secured using some kind of security policy and parameters. The perimeter routers must be secured so that the corporate LAN resources are protected from the outside world.
Perimeter security comes in different forms. If you have a small network with only one router separating you from the rest of the world, it becomes imperative that the perimeter router be secured. This security helps you protect your internal resources.
Perimeter Router and PIX Firewall
Medium-size businesses can take security to the next level by deploying a firewall between the perimeter router and the internal network. The perimeter router provides support to the firewall by filtering out unnecessary traffic from coming into the network.
Perimeter Router Running the Firewall Feature Set
If you are a small- to medium-size network, you can use Cisco routers as a firewall as well. You have to load the firewall feature set on the router. Once the firewall feature set is installed on the router, you can then configure it to provide protection to your network using packet filtering.
You must understand that the firewall feature set does not provide the same level of protection as the PIX Firewall.
Perimeter Router, Firewall, and Internal Router
Large businesses use a three-tiered approach to network security. The perimeter routers provide preliminary protection to the PIX Firewall. The firewall then does the actual packet filtering, and finally, the internal router ensures that certain VLANs are protected from traffic coming into the corporate LANs.
Once the basics of securing networks are in place, how do we actually secure a Cisco router?