Network gear maker Cisco (CSCO) Systems has made a takeover offer worth more than $20 billion for software maker Splunk (SPLK), The Wall Street Journal reported on Friday, citing people familiar with the matter.

The offer was made recently, and the companies are not in active talks, the newspaper said, citing some of the sources.

Cisco did not immediately respond to a request for comment. Splunk said it does not comment on rumors or speculation.

In November last year, San Francisco-based Splunk announced Doug Merritt had stepped down as its chief executive officer and the company’s chair, Graham Smith, would be the interim CEO.