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Reassign Port Number option for TCP

Document Type Expired Internet-Draft (individual)
Expired & archived
Author Dr. Timothy J. Shepard
Last updated 2004-07-13
RFC stream (None)
Intended RFC status (None)
Stream Stream state (No stream defined)
Consensus boilerplate Unknown
RFC Editor Note (None)
IESG IESG state Expired
Telechat date (None)
Responsible AD (None)
Send notices to (None)

This Internet-Draft is no longer active. A copy of the expired Internet-Draft is available in these formats:


Most TCP connections are protected from spoofing attacks from off- path attackers by their obscurity. This memo suggests that the few TCP connections that aren't so protected today may be protected by making them obscure by using random values for both port numbers. The obvious difficulty with this approach is that the well-known port number is required on the initial SYN to connect to the desired service. A TCP option is proposed which can be used during the SYN and SYN-ACK exchange to request (and accomplish) reassignment of the well known port number to a random value.


Dr. Timothy J. Shepard

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)