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Updated Specification of the IPv4 ID Field

Document Type Replaced Internet-Draft (individual)
Expired & archived
Author Dr. Joseph D. Touch
Last updated 2010-04-08 (Latest revision 2010-03-05)
Replaced by draft-ietf-intarea-ipv4-id-update
RFC stream (None)
Intended RFC status (None)
Stream Stream state (No stream defined)
Consensus boilerplate Unknown
RFC Editor Note (None)
IESG IESG state Replaced by draft-ietf-intarea-ipv4-id-update
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This Internet-Draft is no longer active.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:


The IPv4 Identification (ID) field enables fragmentation and reassembly, and as currently specified is required to be unique within the maximum lifetime on all IP packets. If enforced, this uniqueness requirement would limit all connections to 6.4 Mbps. Because this is obviously not the case, it is clear that existing systems violate the current specification. This document updates the specification of the IP ID field to more closely reflect current practice and to more closely match IPv6, so that the field is defined only when a packet is actually fragmented and that fragmentation occurs only at originating hosts or their equivalent. When fragmentation occurs, this document recommends that the ID field be unique within the reordering context, rather than an arbitrary, unenforced upper bound on packet lifetime.


Dr. Joseph D. Touch

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