Cisco has a reputation of building the company through acquisitions, but it has tended to stay away from the really huge ones. With Splunk, it gets an observability platform that could fit nicely into its security business to help customers better understand security threats, while also helping parse oodles of log data to resolve other problems like helping understand system failures or troubleshoot myriad issues across a broad array of enterprise systems. Under the terms of the deal, Cisco is paying a hefty premium of $157 per share.