Cisco WAN :: How To Block Websites In 2600 Series Router

I am asked to implement the security in campus Network. i.e. In this network we want to block some websites, We don't want to use any 3rd party software or proxy server and content filtering module to block theset.my router IOS is advance securityk9 How to block the website in a Cisco 2600 series router by using the command. What is the access list we need to use to block.Assume we want to restrict,

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Here we are using Cisco 2600 series router and 2900 series switch. In router we are using the2Mb lease line link