UDP Backoff Whitepaper
Publication Date: 17th January 2003Author: Roy Hills This paper discusses how it is possible to determine which implementation of a UDP service is being used from the retransmission backoff pattern. It uses IKE (Internet Key Exchange) as an example UDP service which can be identified in this way, although the technique may also be applicable to other UDP services. The paper also describes an example program called "ike-scan" which is able to discover and identify IPsec VPN systems running IKE. This program is publicly available under the GNU Public License (GPL).
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