Exhibit 21.1

SUBSIDIARIES OF THE REGISTRANT

NAME		JURISDICTION OF ORGANIZATION
F5 Networks Australia Pty. Limited		Australia
F5 Networks SARL		France
F5 Networks GmbH		Germany
F5 Networks Hong Kong Limited		Hong Kong
F5 Networks Japan K.K.		Japan
F5 Networks Korea Ltd.		Korea
F5 Networks Singapore Pte Ltd		Singapore
F5 Networks Limited		United Kingdom
F5 RO, Inc.		Washington, U.S.A.
MagniFire Websystems, Inc.		Delaware, U.S.A.
Swan Labs Corporation		California, U.S.A.
Acopia Networks, Inc.		Delaware, U.S.A.

The names of other subsidiaries are omitted. Such subsidiaries would not, if considered in the aggregate as a single subsidiary, constitute a significant subsidiary within the meaning of Item 601(b)(21)(ii) of Regulation S-K.