Ashish, You can refer to http://www.cisco.com/en/US/docs/ios/12_4t/12_4t11/ips_v5.htmlThis should help you.--Raj

Hi Ashish, You can configure IPS on Cisco 2821.Just load it with an image that supports security features.Here's a good Q&A guide that may help you.http://www.cisco.com/en/US/prod/collateral/iosswrel/ps6537/ps6586/ps6634/prod_qas0900aecd806fc530.ht...