EXHIBIT 5.1


                        [Opinion of Hunton & Williams]

                                August 27, 1999


Newbridge Networks Corporation
600 March Road
Kanata, Ontario K2K 2E6
Canada


                        Newbridge Networks Corporation
                      Registration Statement on Form S-8
                        Offering of Common Shares Under
                        Newbridge Networks Corporation
                  Consolidated Key Employee Stock Option Plan
                  -------------------------------------------

Ladies and Gentlemen:

     We have acted as United States counsel for Newbridge Networks Corporation,
a corporation incorporated under the Canada Business Corporations Act (the
"Company"), in connection with the preparation and filing of a Registration
Statement on Form S-8, which incorporates by reference Registration Statement
Nos. 333-30777, 333-2446, 33-97472, 33-89624, 33-78276, 33-68710, 33-55964, and
33-51538 previously filed by the Company on Form S-8 (collectively, the
"Registration Statements"), under the Securities Act of 1933, as amended,
covering an aggregate of 36,000,000 Common Shares, without par value, of the
Company (the "Common Shares") issuable pursuant to the exercise of stock options
granted under the Newbridge Networks Corporation Consolidated Key Employee Stock
Option Plan (the "Consolidated Plan") and certain predecessor stock option plans
of the Company that have been amalgamated into and replaced by the Consolidated
Plan. We have reviewed the corporate action of the Company in connection with
this matter and have examined such documents, corporate records and other
instruments as we have deemed necessary for purposes of this opinion. In this
examination, except with respect to documents executed by officers of the
Company in our presence, we have assumed the genuineness of all signatures, the
authenticity of all documents submitted to us as originals, the conformity to
original documents of all documents submitted to us as reproductions or
certified copies, and the authenticity of the originals of such latter
documents.


     For purposes of this opinion we have also assumed, with your permission:

          (i)    that the Board of Directors of the Company, or the Employee
     Compensation Committee thereof pursuant to delegated authority, has taken
     all action necessary to authorize the Predecessor Plans (as such plans are
     defined in the Registration Statements), each of which has been amended and
     restated by, and consolidated into, the Consolidated Plan;

          (ii)   that the Board of Directors of the Company, or the Employee
     Compensation Committee thereof pursuant to delegated authority, has taken
     or will take all action necessary to authorize the grant of options to
     purchase Common Shares pursuant to the Consolidated Plan; and

          (iii)  that each option so authorized has been or will be duly granted
to an eligible participant in accordance with the terms and provisions of the
applicable Predecessor Plan, the terms and provisions of which have been
superseded and replaced by the Consolidated Plan, or of the Consolidated Plan.

     Based upon the foregoing and subject to the limitations and qualifications
set forth herein, we are of the opinion that the 36,000,000 Common Shares
offered pursuant to the Registration Statements have been duly allotted and
reserved by the Board of Directors of the Company for issuance upon the exercise
of options and, when the consideration therefor is paid to the Company in
accordance with the terms of such options, that the Common Shares issued to the
persons exercising such options will be duly authorized, validly issued, fully
paid and nonassessable.

     We are members of the bar of the State of New York and, accordingly, we
express no opinion as to the effect of the laws of any jurisdiction other than
the Federal laws of the United States of America and the laws of the State of
New York upon the matters referred to herein, in each case as such laws are in
effect on the date hereof. With respect to matters expressed herein relating to
the Company, to the extent such matters are governed by the laws of the Province
of Ontario and the laws of Canada applicable therein, we have relied on the
opinion of Osler, Hoskin & Harcourt of even date herewith filed as Exhibit 5.2
to the Registration Statements.

     We hereby consent to the filing of this opinion as Exhibit 5.1 to the
Registration Statements and to statements referring to us in Item 5 of the
Registration Statements. By giving such consent, we do not admit that we are
within the category of persons whose consent is required under Section 7 of the
Securities Act of 1933, as amended, or the rules and regulations of the
Securities and Exchange Commission promulgated thereunder.


                                             Very truly yours,

                                             Hunton & Williams