On Wednesday 16 January 2013 02:16, Paul Marks wrote: > On Tue, Jan 15, 2013 at 5:01 PM, Denys Vlasenko > <[email protected]> wrote: > > On Tuesday 15 January 2013 03:44, Kevin Baker wrote: > >> AI_ADDRCONFIG is specified in RFC2553 to only return IPv6 data if an > >> IPv6 interface works; otherwise only return IPv4 data. > >> > >> This fixes wget and possibly others which error out when no IPv6 > >> lookup is available, even with valid IPv4 DNS data coming back. > > > > Did you try to ENABLE_FEATURE_PREFER_IPV4_ADDRESS in .config? > > The purpose of AI_ADDRCONFIG is to prefer IPv6 unless the network > obviously does not support it.
The patch siblission email said: "AI_ADDRCONFIG is specified in RFC2553 to only return IPv6 data if an IPv6 interface works" I can see many cases where that would be hard to determine. If IPv6 address has been autoconfigured on my eth0, does it mean that "an IPv6 interface works"? I don't think so. Router may be blissfully unaware about IPv6 routes (in fact, it may be blissfully unaware about *IPv6 per se*). I looked in the uclibc implementation of AI_ADDRCONFIG, and it's just not clear how poor libc is supposed to know "if an IPv6 interface works". > Wouldn't > ENABLE_FEATURE_PREFER_IPV4_ADDRESS have the effect of avoiding IPv6, > even on modern networks? Yes. I'd hazard to guess that having people with *configured, but non-working IPv4* in addition to working IPv6 is not very likely these days. (They's either have working IPv4, or have it fully deconfigured). The user complaints from the real world seem to confirm it: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=658616 They want to use IPv4 address to connect to the server, if it has one. -- vda _______________________________________________ busybox mailing list [email protected] http://lists.busybox.net/mailman/listinfo/busybox
