Cisco on Tuesday announced plans to purchase cloud-based security company OpenDNS for $635 million in cash and equity awards. It just so happens that Cisco was an investor in a $35 million round of funding for OpenDNS in May 2014, but that's beside the point.

Hilton Romanski, the head of business development at Cisco, said the acquisition will extend their ability to provide customers enhanced visibility and threat protection for unmonitored and potentially unsecure entry points into their network. Furthermore, it will allow them to quickly and efficiently deploy and integrate these capabilities as part of their defense architecture.

OpenDNS has raised roughly $51 million since its inception in 2005 meaning the sale price will result in a nice return for investors.

Romanski added that the service is accessed by more than 65 million users on a daily basis. Many of those users take advantage of the company's free DNS resolution service although as of last year, OpenDNS had more than 10,000 paying clients including big names like BP, Netflix and Nvidia.

As per the agreement, the OpenDNS team will join the Cisco Security Business Group and will be led by Senior Vice President and General Manager David Goeckeler.

The acquisition is expected to close in the first quarter of fiscal year 2016 and is the first major acquisition for Cisco since it announced Chuck Robbins would assume the role of CEO starting next month.