David Yen, most recently executive vice president and general manager of Juniper's fabric and switching technologies unit, has left Juniper to take a job at archrival Cisco, according to sources.
Yen's move, confirmed to CRN by sources with knowledge of the situation, was first reported earlier Monday by All Things D's Kara Swisher.
Yen is believed to be taking over some aspect of Cisco's Unified Computing System (UCS) server business, according to those sources, who could provide no information on Yen's new title.
Cisco declined to comment to CRN Monday.
Yen joined Juniper in 2008 as executive vice president, emerging technologies -- part of an influx of new executive managers into Juniper that continues through the present day. He's perhaps better known in the channel, however, for the two decades he spent at Sun Microsystems.
Juniper earlier this year organized many of the products and development activity related to its Junos software platform into its new Platform Systems Group (PSG).
According to sources, Yen felt slighted by Juniper's choice to appoint Stefan Dyckerhoff, who rejoined Juniper in 2010 from Cisco, to head PSG -- a position Yen wanted, those sources said.