RFC 3931, "Layer Two Tunneling Protocol - Version 3 (L2TPv3)", March 2005

Note: This RFC has been updated by RFC 5641

Errata ID: 2766
Status: Rejected
Type: Editorial
Publication Format(s) : TEXT
Reported By: Teco Boot
Date Reported: 2011-04-04
Rejected by: Brian Haberman
Date Rejected: 2012-05-09

Section 4.1.4 says:

   An LCCE MAY fragment a packet before encapsulating it in L2TP.  For
   example, if an IPv4 packet arrives at an LCCE from a Remote System
   that, after encapsulation with its associated framing, L2TP, and IP,
   does not fit in the available path MTU towards its LCCE peer, the
   local LCCE may perform IPv4 fragmentation on the packet before tunnel
   encapsulation. 

It should say:

   An LCCE MAY fragment a packet before encapsulating it in L2TP.  For
   example, if an IPv4 packet with DF=0 arrives at an LCCE from a Remote System
   that, after encapsulation with its associated framing, L2TP, and IP,
   does not fit in the available path MTU towards its LCCE peer, the
   local LCCE may perform IPv4 fragmentation on the packet before tunnel
   encapsulation. 

Notes:

Following RFC 791, IPv4 packets with the DF flag set shall not fragment such packets. RFC 3931 shall not make a precedent for fragmenting IPv4 packets with DF=1.
--VERIFIER NOTES--
The original text uses MAY so it does not mandate fragmentation behavior.

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