June 30 (Reuters) - Cisco Systems Inc said on Tuesday it would buy OpenDNS, a privately held cloud-based security company, for $635 million in cash and equity awards.

The OpenDNS team will be part of Cisco's security business group, boosting the business in the face of fast-growing, sophisticated cyber attacks.

Cisco was part of a group that invested $35 million in OpenDNS in May last year. (http://bit.ly/1KqDMjV) (Reporting by Abhirup Roy in Bengaluru; Editing by Savio D'Souza)