The shares of Cisco Systems (NASDAQ: CSCO) could be in for a rough start this morning, as the company has been downgraded by two separate brokerage firms.

Banc of America Securities cut the firm to neutral, stating that it was primarily due to valuation. Analyst Tim Long stated that he believes the networker's business is as good as it gets, and therefore sees limited upside to the shares.

Long left his 12-month stock price target at $30. Furthermore, the analyst said in a research note that We believe growth will slow over the next few quarters as the headcount benefit is appreciated, there is less scope for share gains and margins are at a peak.

According to the Dow Jones Newswires, the firm added that growth will slow because margins have peaked and the company already has benefited from new sales people.

Meanwhile, Prudential cut the security from overweight to neutral, stating that expectations are aligned with likely performance, leaving little room for major upside surprises in '07.

In addition, the brokerage firm added that the stock should be range-bound this year until new revenue initiatives start contributing.

The security is definitely vulnerable to additional downgrades. Ahead of today's action, Zacks reported that the Cisco had 14 strong buy ratings, six buys, three holds, and just one sell rating.

Meanwhile, options players have grown extremely pessimistic about the firm. The stock's Schaeffer's put/call open interest ratio rests at an annual high of 0.73. In other words, options speculators have not been more bearishly aligned toward the stock at any other time during the past 52 weeks.