Exhibit 99.6

                              DYNATECH CORPORATION

                        4,983,048 SHARES OF COMMON STOCK
                      INITIALLY OFFERED PURSUANT TO RIGHTS
                         DISTRIBUTED TO STOCKHOLDERS OF
                              DYNATECH CORPORATION

To Our Clients:

   Enclosed for your consideration are a Prospectus, dated June 1, 2000 and the
Instructions as to Use of Dynatech Corporation Subscription Warrants relating
to an offer by Dynatech Corporation ("Dynatech") to issue additional shares
(the "Shares") of its common stock (the "Common Stock") at a subscription price
of $4.00 per Share, in cash (the "Subscription Price"), pursuant to
subscription rights (the "Rights") initially distributed to holders of record
("Record Owners") of shares of Common Stock as of the close of business on
April 20, 2000 (the "Record Date").

   As described in the Prospectus, you have received 0.389 Rights for each
share of Common Stock carried by us in your account as of the Record Date. The
Rights are nontransferable and no fractional Rights will be granted; if a
fractional Right would be calculated for you as a result of the ratio described
above, the number of Rights granted to you has been rounded down to the nearest
whole Right. You are entitled to subscribe for one Share for each whole Right
granted to you (the "Basic Subscription Privilege") at the Subscription Price.
You will also have the right (the "Oversubscription Privilege"), subject to
proration, to subscribe for Shares available after satisfaction of all
subscriptions pursuant to the Basic Subscription Privilege at the Subscription
Price. If there are insufficient additional Shares to satisfy all exercised
Oversubscription Privileges, such additional Shares will be allocated pro rata
among all the holders of the Rights exercising Oversubscription Privileges, in
proportion to the number of Shares each such holder has purchased pursuant to
his or her respective Basic Subscription Privilege. You must elect to exercise
your Oversubscription Privilege (or not) at the time you exercise your Basic
Subscription Privilege, and you must exercise your Basic Subscription Privilege
in full in order to exercise your Oversubscription Privilege.

   The materials enclosed are being forwarded to you as the beneficial owner of
the shares of Common Stock held by us in your account. Exercises of the Rights
may be made only by us as the record owner of your Common Stock and pursuant to
your instructions. Accordingly, we request instructions as to whether you wish
us to elect to subscribe for any Shares to which you are entitled pursuant to
the terms and subject to the conditions set forth in the enclosed Prospectus
and "Instructions as to Use of Dynatech Corporation Subscription Warrants."
However, we urge you to read the enclosed documents carefully before
instructing us to exercise your Rights.

   Your instructions to us should be forwarded as promptly as possible in order
to permit us to exercise Rights on your behalf in accordance with the
provisions of the offering described in the Prospectus. The offering will
expire on June 19, 2000, at 5:00 P.M., New York City time, unless the offering
is extended by Dynatech. Once you have exercised your Rights, such exercise may
not be revoked.

   If you wish to have us, on your behalf, exercise your Rights for any Shares
for which you are entitled to subscribe, please so instruct us by completing,
executing and returning to us the instruction form on the reverse side of this
letter.

   Any questions or requests for assistance concerning the offering should be
directed to Mackenzie Partners, Inc., the information agent for this offering,
at 156 Fifth Avenue, New York, NY 10010. You may call Mackenzie Partners, Inc.
toll free at 1 (800) 322-2855.