Cisco Shreds 'Net Neutrality'

With the net neutrality debate set aside for a bit, Cisco (CSCO Quote) spies an opportunity in network gatekeeping.

The San Jose, Calif., Internet gearmaker said Thursday that it acquired network security specialist IronPort for $830 million in stock and cash -- the second-biggest sum Cisco has ever paid for a private company.

San Bruno, Calif.-based IronPort develops software and security equipment that helps network operators block unwanted traffic such as spam and system-crippling applications such as spyware. The company has been particularly effective in filtering email by judging the source's reputation.

Using a system called SenderBase, which the company calls "the world's largest email and Web threat detection network and database," IronPort creates a list of undesirable emailers, effectively a blacklist barring entry to the system. ...