On Sun, 2007-10-14 at 15:15 -0600, Topher wrote: > Ulrich Drepper wrote: > > Les Mikesell 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) the sorting will not change the order in > > which the entries are returned. Hence the RR DNS will not lose its effect. > > > > This debate has splintered a bit on the list, but it seems to me that > everybody's concern has to do with this unfamiliar sorting algorithm. > Am I right, or does somebody have another concern, unrelated to the > sorting algorithm? Sorting is the only point we are discussing. > Ulrich's last comment made me think that DNS results will be sorted a > lot less than people seem to think. It also seems that the biggest > cause of this whole misunderstanding is that Ulrich appears to be the > only one who understands when and how this mysterious sorting algorithm > is applied. Not mysterious at all, read the RFC (easier) and glibc source code and you'll know all about it. > Ulrich: Is there a clear spec that outlines the behavior of this > function, or will we just have to go examine the source code? I think > that if we all had a more realistic and concrete idea about how this > function performs, that we'd all sleep better tonight. :) I didn't see the code diverge much from the RFC, but I didn't do a strict analysis either, just enough to be concerned about the artificial (for IPv4) difference between site-local and global scope addresses (which is dictated by the RFC). That's my principal concern, so far. Simo. -- fedora-devel-list mailing list fedora-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-devel-list
