IPv6 Fragment Overlap not Forbidden

"Elwyn Davies" <elwynd@nortelnetworks.com> Thu, 23 September 2004 14:26 UTC

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From: Elwyn Davies <elwynd@nortelnetworks.com>
To: "'ipv6@ietf.org'" <ipv6@ietf.org>
Date: Thu, 23 Sep 2004 16:20:14 +0200
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Subject: IPv6 Fragment Overlap not Forbidden
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While writing the recent draft on NAT-PT deprecation, I had occasion to
review RFC1838 and RFC3128 which relate to security threats with fragmented
IPv4 packets.  One of the problems was that the IPv4 specification allowed
for fragments to overlap.  It appears that the general assumption is that
IPv6 stacks would not allow fragments to overlap but looking at RFC2460 the
reconstruction algorithm specification does not forbid overlaps. If RFC2460
gets revved this point should be included.

Regards,
Elwyn 

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Elwyn B Davies

        Routing and Addressing Strategy Prime & IPv6 Core Team Leader
        CTO Office, Portfolio Integration		Solutions Ready


        Nortel Networks plc			Email:
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