Re: Question about tcp hash function tcp_hashfn()

On Thu, Jun 01, 2006 at 12:18:25AM -0600, Brian F. G. Bidulock (bidulock@xxxxxxxxxxx) wrote:
Evgeniy,

On Thu, 01 Jun 2006, Evgeniy Polyakov wrote:

for (i=0; i<hash_size*iter_num; ++i) {
saddr = num2ip(get_random_byte(), get_random_byte(), get_random_byte(), get_random_byte());
sport = get_random_word();

You still have a problem: you cannot use a pseudo-random number
generator to generate the sample set as the pseudo-random number
generator function itself can interact with the hash.

Try iterating through all 2**48 values or at least a sizeable
representative subset.

Since pseudo-randomness affects both folded and not folded hash
distribution, it can not end up in different results.

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

--
Evgeniy Polyakov
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