Exhibit 21 COMPUTER NETWORK TECHNOLOGY CORPORATION SUBSIDIARIES OF THE REGISTRANT Articulent Inc. - Incorporated under the laws of the State of Delaware Articulent LLC - Organized under the laws of the State of Minnesota CNT International Ltd. - Incorporated under the English Companies Act - d/b/a CNT International Ltd. and CNTI CNT France S.A. - Incorporated under French law - d/b/a CNT France S.A. and CNTF Computer Network Technology GmbH - Incorporated under German law CNTFS Corporation - Incorporated under Virgin Islands law CNT Deutschland GmbH - Incorporated under German law Computer Network Technology (Asia Pacific) Pty. Ltd. - Incorporated under Australian law - d/b/a CNT A/P CNT China Limited - Incorporated under Hong Kong law CNT Japan K.K. - Incorporated under Japanese law CNT Acquisition I Corporation (formerly known as RealLegacy.com, Inc. and also formerly known as Propelis Software, Inc.) - Incorporated under Minnesota law Computer Network Technology do Brasil Ltda. - Incorporated under Brazilian law