Henry Nothhaft

HENRY ‘HANK’ NOTHHAFT joined Concentric Network Corporation as President
and CEO in May 1995, a Director of the Company in August 1995 and
Chairman of the Board in January 1998. From 1989 to 1994, he was
President, Chief Executive Officer and a Director of David Systems,
Inc., a network company. From 1983 to 1989, he held various positions
with DSC Communications Corporation, including President of the Business
Network Systems Group, President of Digital Switch Corporation
subsidiary, and Senior Vice President of Marketing, in addition to
serving as a Member of the Board of Directors. From 1979 to 1983, Mr.
Nothhaft was Vice President of Domestic Marketing and Vice President of
Sales for GTE Telenet Communications Corporation (now Sprint). He has an
M.B.A. in Information Systems Technology from George Washington
University and a B.S. degree from the U.S. Naval Academy, and is a
former officer in the U.S. Marine Corps.