Hi,
Have a look at the following docs as a start:
http://www.cisco.com/c/en/us/support/docs/ip/access-lists/13608-21.html
http://www.cisco.com/c/en/us/about/security-center/increase-security-ios-xr-devices.html
http://www.cisco.com/c/en/us/products/collateral/switches/nexus-7000-series-switches/guide_c07-665160.html
Thanks
John
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