RFC 4271, "A Border Gateway Protocol 4 (BGP-4)", January 2006

Note: This RFC has been updated by RFC 4724, RFC 6286, RFC 6608, RFC 6793, RFC 7606, RFC 7607, RFC 7705, RFC 8212, RFC 8654, RFC 9072, RFC 9687

Errata ID: 5001
Status: Held for Document Update
Type: Technical
Publication Format(s) : TEXT
Reported By: John Scudder
Date Reported: 2017-04-19
Held for Document Update by: Alvaro Retana
Date Held: 2017-04-27

Section 5 says:

   BGP implementations MUST recognize all well-known attributes.  Some
   of these attributes are mandatory and MUST be included in every
   UPDATE message that contains NLRI.  Others are discretionary and MAY
   or MAY NOT be sent in a particular UPDATE message.

It should say:

   BGP implementations MUST recognize all well-known attributes.  Some
   of these attributes are mandatory and MUST be included in every
   UPDATE message that contains NLRI.  Others are discretionary and may
   or may not be sent in a particular UPDATE message.

Notes:

The original text uses "MAY NOT" capitalized as if it were an RFC 2119 keyword. However, RFC 2119 does not have any defined meaning for "MAY NOT". In context, it is unlikely the reader would be at risk of misinterpreting the text, but nonetheless it's a misuse of RFC 2119 terminology and difficult to parse if reading closely.

(The replacement text was suggested by Eric Rosen; thanks.)

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I updated the Corrected Text to simply use lower case wording, eliminating any rfc2119-related confusion. -- Alvaro.

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