Re: Question about tcp hash function tcp_hashfn()

Evgeniy,

On Thu, 01 Jun 2006, Evgeniy Polyakov wrote:

On Thu, Jun 01, 2006 at 12:46:08AM -0600, Brian F. G. Bidulock (bidulock@xxxxxxxxxxx) wrote:
Since pseudo-randomness affects both folded and not folded hash
distribution, it can not end up in different results.

Yes it would, so to rule out pseudo-random effects the pseudo-
random number generator must be removed.


You are right that having test with 2^48 values is really interesting,
but it will take ages on my test machine :)

Try a usable subset; no pseudo-random number generator.

I've run it for 2^30 - the same result: folded and not folded Jenkins
hash behave the same and still both results produce exactly the same
artifacts compared to XOR hash.

But not without the pseudo-random number generation... ?


Btw, XOR hash, as completely stateless, can be used to show how
Linux pseudo-random generator works for given subset - it's average of
distribution is very good.

But its distribution might auto-correlate with the Jenkins function.
The only way to be sure is to remove the pseudo-random number generator.

Just try incrementing from, say, 10.0.0.0:10000 up, resetting port number
to 10000 at 16000, and just incrementing the IP address when the port
number wraps, instead of pseudo-random, through 2^30 loops for both.
If the same artifacts emerge, I give in.

Can you show the same artifacts for jenkins_3word?

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