[j-nsp] Hash algorithms for LAG

[Thomas Eichhorn]

Dear all,

I just had some discussions with our SE about the
hashing algorithms used in different devices for
packet distribution on LAG.

This seems to be a horrible complexe topic, with
much sensible information behind - the exact algorithm
seems to be much of a secret.

I just wonder why, maybe my idea ist just a little
bit naive, but I hope somebody here can bring some clarification
into it:

If I were to implement such a distribution algorithm,
I would just define a range of bits of the headers,
and do a modulo (number of member links) with it.

The range of bits could say: Only from Byte 9 to 20 for
using the mac-adresses, or a longer part of the header
if including MPLS-labels.

Am I completely wrong and there is much more magic
behind? Has somebody here an deep insight and might
share it with us?

Thanks
Tom