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Re: gethostby* users



Ulrich Drepper wrote:

But, if they
resort the list, half of them will pick the wrong first choice even when
it is reachable.

No.  The sorting performed is not a universal and complete ordering.
For once, it depends on the addresses of the client machines.  Second,
if all target addresses are equally "bad" (i.e., for IPv4, all have the
same matching prefix length)

I've not seen 'matching prefix length' to have anything to do with optimal route paths in practice other than the obvious case where one interface of a client is on the same subnet as one of the supplied IP's, which you can only determine by taking subnet masks into consideration.

> the sorting will not change the order in
which the entries are returned.  Hence the RR DNS will not lose its effect.

I don't object to putting same-subnet results first, but I'd want to see some real-world statistics before jumping to the conclusion that any other change is for the better. I'd venture a guess that the majority of public DNS results are returned by 'intelligent' DNS servers that have already made some effort to give you the right choices in the right order. Maybe we could at least ask someone at google if we need to second-guess their server results.

--
  Les Mikesell
   lesmikesell gmail com


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