Re: [Ipsec] Minor comment/question on draft-ietf-ipsec-esp-v3-09.txt

> From: Stephen Kent <kent@bbn.com>

> Inside the ESP payload, after the optional IV, is the "next layer 
> protocol header." It is referred to as "rest of payload data" in 
> Figure 2. Typically, for transport mode this will be TCP or UDP. For 
> tunnel mode, it is IP. This text is part of a discussion reminding 
> folks that the IV, if present, must preserve the 4 or 8 byte 
> alignment requirements for the relevant IP version. We assume that 
> the ESP payload, overall, started on an appropriate boundary, so the 
> addition of the 8 bytes of SPI plus sequence number preserved this 
> alignment. But the IV, if present, could break the alignment.

I knew that, but I assumed the removal of the ESP headers from the
packet required shifting of data within the packet anyway, so the
aligment requirement seemed unnecessary.

I suppose, it might make some optimizations in the shifting
possible. However, this is a new requirement compared to RFC-2406? Can
it be "MUST"?

_______________________________________________
Ipsec mailing list
Ipsec@ietf.org
https://www1.ietf.org/mailman/listinfo/ipsec