Concentric Network Corporation Relies On Network Appliance for High Performance Storage Solutions.

Business Editors/High-Tech Writers

SUNNYVALE, Calif.--(BUSINESS WIRE)--May 3, 2000

Network Appliance (Nasdaq:NTAP), the leading provider of network-attached data access and content management solutions, announced today that Concentric Network Corporation (Nasdaq:CNCX), a provider of complete Internet business solutions, has reaffirmed Network Appliance as its strategic provider of data storage solutions.

The primary benefits NetApp(R) filers offer Concentric Network are reliability, performance in very large and real-time environments, and architectural flexibility.

Concentric Network has already deployed more than 25 NetApp filers, ranging from F720 economical workgroup file servers to F760s, the most powerful Network Appliance(TM) enterprise storage solution. Network Appliance filers store and serve customer Web site data and power most of Concentric's core services, as well as internal IT functions for Concentric and companies it has acquired.

"Concentric has relied on Network Appliance as its primary storage vendor for four years, and they've grown with us to continue providing the class of filer required to support powerful Internet products," said David Schairer, vice president and chief systems architect, Concentric Network Corporation. "Concentric develops very advanced software and systems solutions to drive its service and network products and requires very high-performing hardware solutions to make them run. We expect Network Appliance to continue to be a strong partner for us in the future."

"We are especially pleased that Concentric has reaffirmed Network Appliance as its vendor of choice for storage solutions in light of the fact that Concentric has such high performance and reliability standards for storage products and continues to evaluate and test competing solutions," said Mark Santora, vice president of marketing at Network Appliance. "We will continue improving our products to keep pace with the sophistication and demands of Concentric's service offerings."

Concentric Network is a participant in the Network Appliance "Powered by Network Appliance" program, which is designed to enhance the exposure and sales of Internet companies that use Network Appliance technology in their mission-critical data centers. Leading dot-com, e-business, ISP, and ASP companies throughout the world that rely on Network Appliance products and services collaborate with Network Appliance on such activities as press release support, comarketing programs, and Web advertising programs.

About Concentric Network Corporation

Concentric Network Corporation provides complete Internet business solutions for small- and medium-sized enterprises, including DSL access, Web hosting, and e-commerce. The company also offers data center services, virtual private networks, dedicated access, global transit, and application infrastructure services for delivering applications over the Internet or a VPN. Concentric's services are offered through a worldwide network of data centers and a private, nationwide ATM network, in addition to an extensive European network and transatlantic capacity. All Concentric services are backed by 24x7 customer care and most include service level agreements. Publicly traded (Nasdaq:CNCX), Concentric Network is headquartered in San Jose, Calif., with operations offices in Irvine, Calif.; Chicago, Ill.; St. Louis, Mo.; Saginaw, Mich.; Secaucus, N.J.; London, United Kingdom; Manchester, United Kingdom; Birmingham, United Kingdom; and Almere, Netherlands, along with sales and channel support worldwide. For more information, visit http://www.concentric.net/ or contact public relations at [e-mail].

About Network Appliance

Network Appliance, a veteran in network file serving and caching, has been providing data access solutions since 1992, and is a member of both the S+P 500 and NASDAQ 100 index. Major corporations and ISPs, including Lycos, Yahoo!, Citicorp Securities, Siemens, Lockheed, Cisco, Motorola, and Texas Instruments have deployed NetApp solutions. NetApp Internet caching solutions (NetCache(TM) appliances) and file servers (filers) deliver fast, simple, reliable, and cost-effective access to network-stored data and enable simultaneous shared file services for UNIX(R), Windows NT(R) and the World Wide Web.

The company pioneered the concept of the "network appliance," an extension of the industry trend toward dedicated, specialized products that perform a single function. Network Appliance filers and NetCache appliances are based on the company's innovative data access software known as the Data ONTAP(TM) operating system and standards-compliant hardware. More information is available at www.netapp.com.

On January 10, 2000, NEXTLINK and Concentric Network announced a $2.9 billion transaction to combine the companies. The transaction is expected to close in the second quarter of this year. NEXTLINK provides high-quality, broadband communications services to businesses over fiber optic and broadband wireless facilities across the United States. NEXTLINK currently is providing service in 49 markets.

Note to Editors: NetApp and the Network Appliance logo are registered trademarks and Network Appliance, NetCache, and Data ONTAP are trademarks of Network Appliance, Inc. in the U.S. and other countries. Concentric Network Corporation is a registered trademark, and the Concentric logo and ConcentricHost are trademarks of Concentric Network Corporation. Windows and Windows NT are registered trademarks of Microsoft Corporation. UNIX is a registered trademark in the U.S. and other countries, licensed exclusively through X/Open Company Limited. All other brands or products are trademarks or registered trademarks of their respective holders and should be treated as such.