Foundry Networks

( FDRY) plunged 12% Tuesday after slashing first-quarter revenue goals due to weak business.

The computer networking shop expects to post per-share net income of between 6 cents and 7 cents on sales of $84 million for the quarter ended in March. Analysts were looking for a dime-a-share profit on $104 million in sales.

"We experienced a slowdown in our U.S. federal government orders," said CEO Bobby Johnson. "Second, our sales to North American enterprise customers were below our initial forecast for the period."

The news wasn't well received by

Cisco Systems

(CSCO) - Get Report

investors, who had been hoping that tech spending was holding steady. Earlier Tuesday, Merrill Lynch upgraded Cisco to a buy, citing its growth outlook and low valuation. Cisco shares rose a quarter in regular action Tuesday before giving some of that gain back in after-hours action.

Foundry shares dropped $1.11 to $8.49 after they were halted briefly early in postclose trading. Rival

Extreme Networks

(EXTR) - Get Report

slipped 3%, and Cisco dropped 8 cents to $18.16 in late trading Tuesday.

Foundry is expected to report earnings April 21.