RFC Errata
RFC 791, "Internet Protocol", September 1981
Note: This RFC has been updated by RFC 1349, RFC 2474, RFC 6864
Source of RFC: LegacyArea Assignment: int
See Also: RFC 791 w/ inline errata
Errata ID: 7561
Status: Verified
Type: Editorial
Publication Format(s) : TEXT
Reported By: Fernando Gont
Date Reported: 2023-07-10
Verifier Name: Eric Vyncke
Date Verified: 2023-08-03
Section 3.2 says:
Identification
The choice of the Identifier for a datagram is based on the need to
provide a way to uniquely identify the fragments of a particular
datagram. The protocol module assembling fragments judges fragments
to belong to the same datagram if they have the same source,
destination, protocol, and Identifier. Thus, the sender must choose
the Identifier to be unique for this source, destination pair and
protocol for the time the datagram (or any fragment of it) could be
alive in the internet.
It seems then that a sending protocol module needs to keep a table
of Identifiers, one entry for each destination it has communicated
with in the last maximum packet lifetime for the internet.
However, since the Identifier field allows 65,536 different values,
some host may be able to simply use unique identifiers independent
of destination.
It should say:
Identification
The choice of the Identification for a datagram is based on the need to
provide a way to uniquely identify the fragments of a particular
datagram. The protocol module assembling fragments judges fragments
to belong to the same datagram if they have the same source,
destination, protocol, and Identification. Thus, the sender must choose
the Identification to be unique for this source, destination pair and
protocol for the time the datagram (or any fragment of it) could be
alive in the internet.
It seems then that a sending protocol module needs to keep a table
of Identification values, one entry for each destination it has communicated
with in the last maximum packet lifetime for the internet.
However, since the Identification field allows 65,536 different values,
some host may be able to simply use unique identifiers independent
of destination.
Notes:
The field is called "Identification", and not "Identifier" (please note the capitalization in the text).