Re: [BEHAVE] How to set the DF and the ID values for IPv4 packets (was Re: Amount of fragmentation resulting from translation

[Iljitsch van Beijnum <iljitsch at muada.com>]

[FYI: my emails to you always bounce, please fix, it is really  
annoying.]

On 2 nov 2009, at 20:38, Fernando Gont wrote:

> For *this* is scenario (xlat), my recommendation would be a RFC1948- 
> like
> scheme:

> ID = counter + F()

> Where F() is a hash function that takes src IPv4, Dst IPv4, Protocol,
> and secret_key as parameters.

What are the de facto benefits of performing such an expensive  
operation (a hash function) for each packet?

You didn't answer me on a similar question why it would be beneficial  
to introduce the extra state required to rewrite the sequence numbers  
for TCP sessions, by the way.