Filed Pursuant to Rule 424(b)(3)
Registration No. 333-106889
PROSPECTUS SUPPLEMENT DATED OCTOBER 13, 2004
(To Prospectus filed on November 21, 2003)
JUNIPER NETWORKS, INC.
$400,000,000
      Zero Coupon Convertible Subordinated Notes due June 15, 2008 and 19,860,973 Shares of Common Stock Issuable Upon Conversion of the Notes
     This Prospectus Supplement, together with the Prospectus listed above, is to be used by certain holders of the above-referenced securities or by their transferees, pledgees, donees or their successors in connection with the offer and sale of the above referenced securities.
     The table captioned “Selling Security Holders” commencing on page 29 of the Prospectus is hereby amended to reflect the following additions and changes. 

 	 	Principal Amount at	 	 	 	 	 	 	 	 	
 	 	Maturity of Notes	 	 	 	 	 	Number of Shares of	 	Percentage of	
 	 	Beneficially Owned	 	Percentage of Notes	 	Common Stock That	 	Common Stock	
Name	 	That May Be Sold	 	Outstanding(1)	 	May Be Sold(2)	 	Outstanding(3)	
	 		 		 		 		
UBS AG London F/B/O HFS	 	$	25,000,000	 	 	 	6.25	%	 	 	1,241,310	 	 	 	*	 	
UBS AG F/B/O IPB Client	 	 	22,500,000	 	 	 	5.63	%	 	 	1,117,179	 	 	 	*	 	
JP Morgan Securities, Inc.(25)	 	 	9,500,000	 	 	 	2.38	%	 	 	471,698	 	 	 	*	 	
Aviator Master Fund(26)	 	 	3,757,000	 	 	 	*	 	 	 	186,544	 	 	 	*	 	
Aviator Overseas Fund II, Ltd.(26)	 	 	343,000	 	 	 	*	 	 	 	17,030	 	 	 	*	 	

* 	 	Less than 1%	

(1)	 	Based on $400,000,000 principal amount of notes outstanding.	

(2)	 	Assumes conversion of all of the holder’s notes at a conversion price of approximately $20.14 per share of common stock. However, this conversion price will be subject to adjustment as described under the section entitled “Description of the Notes-Conversion Rights.” As a result, the amount of common stock issuable upon conversion of the notes may increase or decrease in the future.	

(3)	 	Calculated based on Rule 13d-3(d)(i) of the Exchange Act using 387,916,534 shares of common stock outstanding as of September 30, 2003. In calculating this amount, we treated as outstanding the number of shares of common stock issuable upon conversion of all of that particular holder’s notes. However, we did not assume the conversion of any other holder’s notes. Assumes that any other holders of notes, or any future transferees, pledgees, donees or successors of or from any such other holders of notes, do not beneficially own any common stock other than the common stock issuable upon conversion of the notes at the initial conversion rate.	

(25)	 	Broker-Dealer, based upon information provided to the Company by such Selling Security Holder.	

(26)	 	William Park has investment control over the securities beneficially owned by this Selling Security Holder.