Cisco's weak revenue forecast is driving down its stock (CSCO)

Cisco topped Wall Street's revenue target in its fiscal Q4, but gave a lackluster business forecast for the current quarter.
Cisco's stock declined roughly 2% in after hours trading on Wednesday following the announcement.
Here's are Cisco's results:
Revenue (GAAP) — $12.1 billion, down 4% from $12.64 billion in Q4 2016.  This is compared to analyst estimates of $12.07 billion. Cisco projected similar estimates. 
Earnings per share (adjusted) — $0.6