How to connect VPN concentrator to CISCO Router

Introduction
This sample configuration shows how to connect a private network behind a router that runs Cisco IOS® software to a private network behind the Cisco VPN 3000 Concentrator. The devices on the networks know each other by their private addresses.
Prerequisites
Requirements
There are no specific requirements for this document.
Components Used
The information in this document is based on these software and hardware versions:
Cisco 2611 router with Cisco IOS Software Release 12.3.(1)a
Note: Make sure that Cisco 2600 Series routers are installed with a crypto IPsec VPN IOS image that supports the VPN feature.
Cisco VPN 3000 Concentrator with 4.0.1 B
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.
Conventions
Refer to Cisco Technical Tips Conventions for more information on document conventions.
Configure
In this section, you are presented with the information to configure the features described in this document.
Note: Use the Command Lookup Tool ( registered customers only) to find more information on the commands used in this document.