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Inappropriate TCP Resets Considered Harmful

The information below is for an old version of the document that is already published as an RFC.
Document Type
This is an older version of an Internet-Draft that was ultimately published as RFC 3360.
Author Sally Floyd
Last updated 2015-10-14 (Latest revision 2002-05-08)
RFC stream Legacy stream
Intended RFC status Best Current Practice
Stream Legacy state (None)
Consensus boilerplate Unknown
RFC Editor Note (None)
IESG IESG state Became RFC 3360 (Best Current Practice)
Action Holders
Telechat date (None)
Responsible AD Steven M. Bellovin
IESG note
Send notices to (None)
A new Request for Comments is now available in online RFC libraries.

        BCP 60
        RFC 3360

        Title:      Inappropriate TCP Resets Considered Harmful
        Author(s):  S. Floyd
        Status:     Best Current Practice
        Date:       August 2002
        Pages:      19
        Characters: 46748
        SeeAlso:    BCP 60

        I-D Tag:    draft-floyd-tcp-reset-04.txt


This document is being written because there are a number of
firewalls in the Internet that inappropriately reset a TCP connection
upon receiving certain TCP SYN packets, in particular, packets with
flags set in the Reserved field of the TCP header.  In this document
we argue that this practice is not conformant with TCP standards, and
is an inappropriate overloading of the semantics of the TCP reset.
We also consider the longer-term consequences of this and similar
actions as obstacles to the evolution of the Internet infrastructure.

This document specifies an Internet Best Current Practices for the
Internet Community, and requests discussion and suggestions for
improvements.  Distribution of this memo is unlimited.

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