**Exhibit 31.1**

 

**Certificationof Principal Executive Officer**

 

I, Bruce L. Claflin, certifythat:

 

1.                                       I have reviewedthis quarterly report on Form 10-Q of 3Com Corporation;

 

2.                                       Based on myknowledge, this report does not contain any untrue statement of a material factor omit to state a material fact necessary to make the statements made, inlight of the circumstances under which such statements were made, notmisleading with respect to the period covered by this report;

 

3.                                       Based on myknowledge, the financial statements, and other financial information includedin this report, fairly present in all material respects the financialcondition, results of operations and cash flows of the registrant as of, andfor, the periods presented in this report;

 

4.                                       The registrant’sother certifying officer(s) and I are responsible for establishing andmaintaining disclosure controls and procedures (as defined in Exchange ActRules 13a-15(e) and 15d-15(e)) for the registrant and have:

 

(a)                                  Designed suchdisclosure controls and procedures, or caused such disclosure controls and proceduresto be designed under our supervision,to ensure that material information relating to the registrant,including its consolidated subsidiaries, is made known to us by others withinthose entities, particularly during the period in which this report is beingprepared;

 

(b)                                 [Paragraph omitted pursuant to SECRelease Nos. 33-8238 and 34-47986]

 

(c)                                  Evaluated theeffectiveness of the registrant’s disclosure controls and procedures andpresented in this report our conclusions about the effectiveness of thedisclosure controls and procedures, as of the end of the period covered by thisreport based on such evaluation; and

 

(d)                                 Disclosed inthis report any change in the registrant’s internal control over financialreporting that occurred during the registrant’s most recent fiscal quarter (theregistrant’s fourth fiscal quarter in the case of an annual report) that hasmaterially affected, or is reasonably likely to materially affect, theregistrant’s internal control over financial reporting; and

 

5.                                       Theregistrant’s other certifying officer(s) and I have disclosed, based on ourmost recent evaluation of internal control over financial reporting, to theregistrant’s auditors and the audit committee of the registrant’s board ofdirectors (or persons performing the equivalent functions):

 

(a)                                  All significantdeficiencies and material weaknesses in the design or operation of internalcontrol over financial reporting which are reasonably likely to adversely affectthe registrant’s ability to record, process, summarize and report financialinformation; and

 

(b)                                 Any fraud,whether or not material, that involves management or other employees who have asignificant role in the registrant’s internal control over financial reporting.

 
| Date:  | October 5, 2004                                                 |   |   |
|--------|----------------------------------------------------------------------|--------|--------|
|   |                                                                 |
|   | /s/        BRUCE  L. CLAFLIN |   |
|   | Bruce L. Claflin                                                     |
|   | President and Chief  Executive Officer                               |

 

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