I-BLOG

Productivity increase by blocking non-project related sites is one of the myth that I’ve seen a lot on various online forums and as well there are always counter research data as to this has nothing to do with ‘increase in productivity’. I guess, I kinda agree too (Well, I know one of the leading IT companies who doesn’t give computers with internet access to any employee and only the lead/manager has it, that too restricted).

So putting aside the arguments, one of the issues with blocking outgoing connections based on IP has always failed (imagine the cloud of servers, if you were to block say yahoo mail). Now the Modular Policy Framework does support regex checking in the URL header to see which site it is going and block it, if you’d like to.

Here is the Cisco article describing the MPF in details {Here}

Now how do you block say access to facebook or myspace, from being utilized by your employees?? Pete has a good write-up on it and hence I’m not going to write it again here.

In short the configuration you need is; Thanks to Pete for providing such a detailed write-up.

On the Global Policy
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regex domainlist1 "facebook.com"
class-map type regex match-any DomainBlockList 
  match regex domainlist1 
class-map type inspect http match-all BlockDomainsClass
  match request header host regex class DomainBlockList
policy-map type inspect http http_inspection_policy 
class BlockDomainsClass
  reset log
policy-map global_policy
  class inspection_default
  inspect http http_inspection_policy
service-policy global_policy global
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With its own policy

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regex BLOCKED_DOMAIN_1 "www.facebook.com"
access-list TRAFFIC_TO_INSPECT_FOR_BLOCKED_DOMAINS extended permit tcp any any eq http
class-map type regex match-any CLASS_MAP_BLOCKED_DOMAIN_LIST
  match regex BLOCKED_DOMAIN_1
class-map type inspect http match-all CLASS_MAP_DEFINE_TRAFFIC_TO_INSPECT
  match request header host regex class CLASS_MAP_BLOCKED_DOMAIN_LIST
class-map CLASS_MAP_HTTP_TRAFFIC
  match access-list TRAFFIC_TO_INSPECT_FOR_BLOCKED_DOMAINS
policy-map type inspect http POLICY_MAP_HTTP_INSPECTION
  parameters
  class CLASS_MAP_DEFINE_TRAFFIC_TO_INSPECT
  drop-connection log
policy-map POLICY_MAP_OUTSIDE_INTERFACE
class CLASS_MAP_HTTP_TRAFFIC
  inspect http POLICY_MAP_HTTP_INSPECTION
service-policy POLICY_MAP_OUTSIDE_INTERFACE interface outside