In 2009, I had analyzed Cisco’s strategy of Acquisitions and Development (A&D) which was claimed to be a substitute to R&D. You can have a look at my previous article also entitled Cisco’s A&D. I decided to redo the same analysis, i.e. the size of Cisco per year (sales and employees) as well as the number and values of its acquisitions. I also analyzed the geographical location of these acquisitions. The results follow. I just add that Silicon Valley remains the main source of acquisitions. The total value of the M&As were about $75B ($48B until 2006 and $27B in the last 10 years).
Finally the exhaustive list (from Cisco’s web site and Wikipedia).