Bug#608061: libc6: dns-lookup unusable in mixed ipv4/ipv6-networks
related bug: #582916 but i think the problem only happens if the response for the A record is lost or maybe arrives after the response for the record -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Bug#608061: libc6: dns-lookup unusable in mixed ipv4/ipv6-networks
tag 608061 + unreproducible thanks Your trace proves nothing, this is a tcpdump with no data inside, you give actually no way to reproduce the problem. On Sun, 26 Dec 2010 20:22:28 +0100 Felix Schueller fs-linux_...@fschueller.eu wrote: Package: libc6 Version: 2.11.2-7 Severity: important Tags: ipv6 When looking up an ip-address on an ipv6-enabled system, libc tries to find an A and an -record. But, if some machine has only an A but no record it returns host-not-found (see tcpdump below) So one can only connect (with e.g. iceweasel, w3m, telnet) to hosts with both A and records (or server with cname-records) On an ipv4-only machine this can be solved by disabling ipv6 completly, but on a dualstack-machine, i found no way to fix this. I found this on bug on two ways, an installing squeeze via d-i (the ipv4 only machine) and via upgrading from lenny to squeeze I do have an ipv6 enabled machine here, and I can connect to ipv4-only hosts just fine with w3m or any other programs. Have you modified your /etc/gai.conf, are you using nscd with hosts caching ? -- ·O· Pierre Habouzit ··Omadco...@debian.org OOOhttp://www.madism.org -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Bug#608061: libc6: dns-lookup unusable in mixed ipv4/ipv6-networks
Hello, thanks for your quick reply. Your trace proves nothing, this is a tcpdump with no data inside, you give actually no way to reproduce the problem. Sorry for that, it took me to long find at least an idea whats wrong, so i forgot to use a better dump (strace didn't show something interesting for me) After submitting this bug i disscussed it once again with a friend, and i found one reason for this problem. As i said, i've installed squeeze two times, on different machines in different networks. Both in mixed ipv4/ipv6 networks, working normaly with lenny, but (as i know now) in both networks the (recursive) dns-server is an rather old version of maradns as (1.2X) witch answers to lookups normaly if they exists, but answers strange if no exists. (the full tcpdump looks, as if maradns puts parts of the SOA-info in this answer) libc6 in lenny seams to ignore this, but the libc6 in squeeze reads this as not found. So im not longer shure weather this is a bug, or just something to be dokumented. (i searched a lot, and found not much about problem like this, apart from an old bug (#541167 from 2009) against this pakage) But if you need any further informations, the dns here is now a newer version of maradns and the Problem is gone, but the other machine is still behind the older version, and i can give you some better details (in two weeks) bevor upgrading this server. When looking up an ip-address on an ipv6-enabled system, libc tries to find an A and an -record. But, if some machine has only an A but no record it returns host-not-found (see tcpdump below) So one can only connect (with e.g. iceweasel, w3m, telnet) to hosts with both A and records (or server with cname-records) On an ipv4-only machine this can be solved by disabling ipv6 completly, but on a dualstack-machine, i found no way to fix this. I found this on bug on two ways, an installing squeeze via d-i (the ipv4 only machine) and via upgrading from lenny to squeeze [...] Have you modified your /etc/gai.conf, are you using nscd with hosts caching ? No to both. By Felix -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Bug#608061: libc6: dns-lookup unusable in mixed ipv4/ipv6-networks
Package: libc6 Version: 2.11.2-7 Severity: important Tags: ipv6 When looking up an ip-address on an ipv6-enabled system, libc tries to find an A and an -record. But, if some machine has only an A but no record it returns host-not-found (see tcpdump below) So one can only connect (with e.g. iceweasel, w3m, telnet) to hosts with both A and records (or server with cname-records) On an ipv4-only machine this can be solved by disabling ipv6 completly, but on a dualstack-machine, i found no way to fix this. I found this on bug on two ways, an installing squeeze via d-i (the ipv4 only machine) and via upgrading from lenny to squeeze example-tcpdump 19:47:46.941816 IP d64.w12a.fschueller.eu.57717 ns.w12a.fschueller.eu.domain: 6813+ A? www.spiegel.de. (32) 19:47:46.942592 IP d64.w12a.fschueller.eu.47213 ns.w12a.fschueller.eu.domain: 36087+ PTR? 254.1.168.192.in-addr.arpa. (44) 19:47:46.942768 IP ns.w12a.fschueller.eu.domain d64.w12a.fschueller.eu.57717: 6813- 1/0/0 A 195.71.11.67 (48) 19:47:46.942989 IP d64.w12a.fschueller.eu.57717 ns.w12a.fschueller.eu.domain: 10783+ ? www.spiegel.de. (32) 19:47:46.944994 IP ns.w12a.fschueller.eu.domain d64.w12a.fschueller.eu.47213: 36087*- 1/1/1 PTR ns.w12a.fschueller.eu. (109) 19:47:46.945315 IP d64.w12a.fschueller.eu.51939 ns.w12a.fschueller.eu.domain: 54899+ PTR? 3.1.168.192.in-addr.arpa. (42) 19:47:46.946277 IP ns.w12a.fschueller.eu.domain d64.w12a.fschueller.eu.57717: 10783- 0/1/0 (85) 19:47:46.947048 IP d64.w12a.fschueller.eu.56975 ns.w12a.fschueller.eu.domain: 6813+ A? www.spiegel.de. (32) 19:47:46.947146 IP d64.w12a.fschueller.eu.56975 ns.w12a.fschueller.eu.domain: 10783+ ? www.spiegel.de. (32) 19:47:46.948986 IP ns.w12a.fschueller.eu.domain d64.w12a.fschueller.eu.51939: 54899*- 1/1/1 PTR d64.w12a.fschueller.eu. (111) 19:47:46.949616 IP ns.w12a.fschueller.eu.domain d64.w12a.fschueller.eu.56975: 6813- 1/0/0 A 195.71.11.67 (48) 19:47:46.950718 IP ns.w12a.fschueller.eu.domain d64.w12a.fschueller.eu.56975: 10783- 0/1/0 (85) 19:47:46.951418 IP d64.w12a.fschueller.eu.40332 ns.w12a.fschueller.eu.domain: 59564+ A? www.spiegel.de.w12a.fschueller.eu. (51) 19:47:46.951583 IP d64.w12a.fschueller.eu.40332 ns.w12a.fschueller.eu.domain: 40272+ ? www.spiegel.de.w12a.fschueller.eu. (51) 19:47:46.953307 IP ns.w12a.fschueller.eu.domain d64.w12a.fschueller.eu.40332: 59564 NXDomain*- 0/1/0 (101) 19:47:46.954779 IP ns.w12a.fschueller.eu.domain d64.w12a.fschueller.eu.40332: 40272 NXDomain*- 0/1/0 (101) 19:47:46.962379 IP d64.w12a.fschueller.eu.37847 ns.w12a.fschueller.eu.domain: 4010+ A? www.spiegel.de. (32) 19:47:46.962585 IP d64.w12a.fschueller.eu.37847 ns.w12a.fschueller.eu.domain: 55074+ ? www.spiegel.de. (32) 19:47:46.963417 IP ns.w12a.fschueller.eu.domain d64.w12a.fschueller.eu.37847: 4010- 1/0/0 A 195.71.11.67 (48) 19:47:46.964467 IP ns.w12a.fschueller.eu.domain d64.w12a.fschueller.eu.37847: 55074- 0/1/0 (85) 19:47:46.965055 IP d64.w12a.fschueller.eu.56559 ns.w12a.fschueller.eu.domain: 4010+ A? www.spiegel.de. (32) 19:47:46.965212 IP d64.w12a.fschueller.eu.56559 ns.w12a.fschueller.eu.domain: 55074+ ? www.spiegel.de. (32) 19:47:46.966084 IP ns.w12a.fschueller.eu.domain d64.w12a.fschueller.eu.56559: 4010- 1/0/0 A 195.71.11.67 (48) 19:47:46.967142 IP ns.w12a.fschueller.eu.domain d64.w12a.fschueller.eu.56559: 55074- 0/1/0 (85) 19:47:46.971000 IP d64.w12a.fschueller.eu.42783 ns.w12a.fschueller.eu.domain: 59661+ A? www.spiegel.de.w12a.fschueller.eu. (51) 19:47:46.971175 IP d64.w12a.fschueller.eu.42783 ns.w12a.fschueller.eu.domain: 40462+ ? www.spiegel.de.w12a.fschueller.eu. (51) 19:47:46.972878 IP ns.w12a.fschueller.eu.domain d64.w12a.fschueller.eu.42783: 59661 NXDomain*- 0/1/0 (101) 19:47:46.974371 IP ns.w12a.fschueller.eu.domain d64.w12a.fschueller.eu.42783: 40462 NXDomain*- 0/1/0 (101) -- System Information: Debian Release: squeeze/sid APT prefers testing APT policy: (500, 'testing') Architecture: amd64 (x86_64) Kernel: Linux 2.6.32-5-amd64 (SMP w/1 CPU core) Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/bash Versions of packages libc6 depends on: ii libc-bin 2.11.2-7 Embedded GNU C Library: Binaries ii libgcc1 1:4.4.5-8 GCC support library libc6 recommends no packages. Versions of packages libc6 suggests: ii debconf [debconf-2.0] 1.5.36 Debian configuration management sy pn glibc-doc none (no description available) ii locales 2.11.2-7 Embedded GNU C Library: National L -- debconf information: * glibc/upgrade: true * glibc/disable-screensaver: glibc/restart-failed: * glibc/restart-services: ssh openbsd-inetd exim4 cups cron -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
