The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 19, 2016
Filed:
May. 15, 2013
Citrix Systems, Inc., Fort Lauderdale, FL (US);
Manikam Muthiah, Bangalore, IN;
CITRIX SYSTEMS, INC., Fort Lauderdale, FL (US);
Abstract
The present solution reduces denial of service (DoS) attacks against dynamically generated next secure (NSEC) records. A domain name system (DNS) proxy may prevent spoofed IP addresses by forcing clients to transmit DNS queries via transmission control protocol (TCP), by replying to a user datagram protocol (UDP) DNS request with a blank or predetermined resource record with a truncation bit set to indicate that the record is too large to fit within a single UDP packet payload. Under the DNS specification, the client must re-transmit the DNS request via TCP. Upon receipt of the retransmitted request via TCP, the DNS proxy may generate fictitious neighbor addresses and a signed NSEC record and transmit the record to the client. Accordingly, the DNS Proxy need not waste time and processor cycles generating and signing records for requests from spoofed IP addresses via UDP.