]] Martin Pitt | Ah, Tollef shed some light on this. Ubuntu's glibc up to early Karmic | had a patch applied which disabled unnecessary IPv6 DNS lookups | (http://err.no/patches/glibc-only-lookup-ipv6-if-it-makes-sense.diff). | This was dropped in Karmic to fix some IPv6 lookup issues (bug 239701, | bug 374674), but also caused this regressions. | | Mithrandir| so I suspect somebody should take my patch, refine it so it | doesn't just reject v6 addresses (try again after processing if there no | hits, allowing ipv6 then, or something like that)
If you want to emulate a broken DNS server (regardless of whether you have access to one), add something like the following iptables rule: sudo iptables -A OUTPUT -p udp --dport 53 \! -f -m u32 --u32 "0 >> 22 & 0x3C @ 8 >> 11 & 0x1F = 0 && 0 >> 22 & 0x3C@ 17 & 0xFF @ 18 & 0xFF @ 21 & 0xFF = 0x1c" -j DROP then try to look up sixxs.net or any other second-level domain. It does not matter whether this actually has AAAA records or not. Assuming you don't have any IPv6 address with scope >= site, this should be slow on 9.10 and fast on 7.04 through 9.04. If you have any IPv6 address with scope >= site, it will be slow on all variants. (The reason for the two-level limitation is due to limitations in the u32 classifier.) -- Tollef Fog Heen UNIX is user friendly, it's just picky about who its friends are -- [karmic regression] all network apps / browsers suffer from multi-second delays by default due to IPv6 DNS lookups https://bugs.launchpad.net/bugs/417757 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
