The agreement has Cisco paying $76 per share in cash in exchange for each share of Sourcefire. The $US2.7bn figure refers to the aggregate purchase price for outstanding equity awards.
Cisco expects the acquisition to be slightly dilutive to non-GAAP earnings in fiscal year 2014 as a result of normal purchase accounting adjustments and integration costs.
All Sourcefire shares are expected to be taken off the NASDAQ stock market by the close of business today.
The agreement sees Cisco's security portfolio expand with the addition of Sourcefire's advanced threat protection solutions, as well as a set of enforcement and remediation options that are integrated, pervasive, continuous, and open.
This will support Cisco's threat-centric security model which is designed to enable customers to address the full attack spectrum.
"To truly protect against all possible attack vectors, our focus is to examine the nature of modern networked environments and devices and to defend them by deeply understanding and analysing the mindset of the attackers," Cisco Security Group senior vice-president, Christopher Young, said.
With the transaction complete, Sourcefire employees join the Cisco Security Group led by Young. Sourcefire founder and CTO, Martin Roesch, will assume the role of vice-president and chief architect of the group, reporting to Young.
In August, Cisco said its 4000 job cuts would not impact Sourcefire.