Goldman Sachs analyst Rod Hall downgraded F5 Networks (FFIV) to Sell from Neutral and lowered his price target for the shares to $120 from $165. The company's earnings risks are increasing due to the weaker short-term spending environment and increasing competitive threat, Hall tells investors in a research note. Enterprise represents ~65% of F5's revenue and short term indications for spending in that market have been weak, says the analyst. Further, he believes VMware (VMW) is now a potential competitor through its proposed acquisition of Avi Networks.