Baystreet Staff - Friday, September 23, 2016 Cisco Systems (CSCO) Slips as Imperva Takeover Rumors Swirl Cisco Systems Inc. (NASDAQ: CSCO) shares gave back 1% to $31.36, amid rumors Cisco might have an interest in buying Imperva Inc. Share volume was 6.9 million, compared to an all-day average of 23 million