|
Slow reverse DNS lookups
![[nl]](/s/countries/nl.gif) Shadow Hawkins on Tuesday, 16 March 2004 17:12:20
I'm experiencing slow reverse DNS lookups using ping6 and traceroute6 on Fedora Core-1 and Redhat 9. Both boxes are running standard rpm's, everything else seems fine. (Mozilla / Apache) Has any of you experienced the same?
Cheers,
Willem.
Slow reverse DNS lookups
You might want to be a bit more specific as to which address you are trying to lookup for instance.
Note also that Fedora and Redhat both had a broken resolver where they are trying to resolve ip6.int, which has been deprecated for over 2 years. ip6.arpa is the standard.
Slow reverse DNS lookups
![[de]](/s/countries/de.gif) Shadow Hawkins on Wednesday, 17 March 2004 13:15:48
Redhat/Fedora's broken DNS resolver did not only use ip6.int, but also bitstring for some time. Some resolver servers timeout when queried for bitstring resulting in slow lookups.
You might want to tcpdump your domain requests while trying to resolve and upgrade your glibc if possible.
Slow reverse DNS lookups
Shadow Hawkins on Wednesday, 17 March 2004 15:26:28
See below result (i guess this is the bitstring you are refering to) Question: which glibc resolves this issue?
-Willem.
------------------------------------------------------------------
ping6 -c 1 www.6net.org
15:23:25.895415 ha-2.dk.eradus.com.32806 > ha-1.dk.eradus.com.domain: 42924+ AAAA? www.6net.org. (30) (DF)
15:23:25.896700 ha-2.dk.eradus.com.32807 > ha-1.dk.eradus.com.domain: 44851+ PTR? 2.223.168.192.in-addr.arpa. (44) (DF)
15:23:25.900212 ha-2.dk.eradus.com.32808 > ha-1.dk.eradus.com.domain: 42925+ PTR? \[x200106100148dead021018fffe020e38/128][|domain] (DF)
15:23:30.904369 ha-2.dk.eradus.com.32808 > ha-1.dk.eradus.com.domain: 42925+ PTR? \[x200106100148dead021018fffe020e38/128][|domain] (DF)
15:23:31.910680 ha-2.dk.eradus.com.32808 > ha-1.dk.eradus.com.domain: 42926+[|domain] (DF)
15:23:31.914961 2001:838:39c::4 > 2001:610:148:dead:210:18ff:fe02:e38: icmp6: echo request
15:23:31.915591 ha-2.dk.eradus.com.32808 > ha-1.dk.eradus.com.domain: 44852+ PTR? \[x200106100148dead021018fffe020e38/128][|domain] (DF)
15:23:31.953090 2001:610:148:dead:210:18ff:fe02:e38 > 2001:838:39c::4: icmp6: echo reply
15:23:31.953620 ha-2.dk.eradus.com.32809 > ha-1.dk.eradus.com.domain: 42927+ PTR? \[x200106100148dead021018fffe020e38/128][|domain] (DF)
15:23:36.924459 ha-2.dk.eradus.com.32808 > ha-1.dk.eradus.com.domain: 44852+ PTR? \[x200106100148dead021018fffe020e38/128][|domain] (DF)
15:23:36.954419 ha-2.dk.eradus.com.32809 > ha-1.dk.eradus.com.domain: 42927+ PTR? \[x200106100148dead021018fffe020e38/128][|domain] (DF)
15:23:37.931279 ha-2.dk.eradus.com.32810 > ha-1.dk.eradus.com.domain: 44853+[|domain] (DF)
15:23:37.931548 ha-2.dk.eradus.com.32811 > ha-1.dk.eradus.com.domain: 42928+[|domain] (DF)
15:23:37.936415 ha-2.dk.eradus.com.32813 > ha-1.dk.eradus.com.domain: 44854+ PTR? \[x20010838039c00000000000000000004/128][|domain] (DF)
15:23:42.944549 ha-2.dk.eradus.com.32813 > ha-1.dk.eradus.com.domain: 44854+ PTR? \[x20010838039c00000000000000000004/128][|domain] (DF)
15:23:43.952945 ha-2.dk.eradus.com.32813 > ha-1.dk.eradus.com.domain: 44855+[|domain] (DF)
Slow reverse DNS lookups
Shadow Hawkins on Wednesday, 17 March 2004 16:16:05
Sorry, dunno which Fedora/Redhat version to use. The appropriate bug is
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=111059
it has been backported to glibc-2.3.2-r9 in Gentoo and it seems that this issue has also been fixed in Debian.
Slow reverse DNS lookups
Shadow Hawkins on Wednesday, 17 March 2004 16:53:43
Thanks, it seems there is no update available for Fedora. Strangely enough an extremely old version of SuSe just works fine!
Willem.
Slow reverse DNS lookups
Shadow Hawkins on Wednesday, 17 March 2004 19:40:26
Yeah, it has been fine (or at least was "use ip6.int in nibble form only") for a long time. Then in September 2003 someone cried on glibc's bugzilla that bitstring was standard (no, it was NOT) and why it wasn't supported. So they added that (without even looking for the current standards!) and broke the whole thing.
IIRC all versions of glibc that have been extracted from CVS between some day in mid of August 2003 and end of January 2004 are broken regarding IPv6 reverse.
Slow reverse DNS lookups
/me makes fun of Berni: use a real distribution ;)
<evil grin>
Debian for instance had some issues with this too but they at least reversed the patch for some while fixing this issue.
Slow reverse DNS lookups
Shadow Hawkins on Wednesday, 17 March 2004 20:01:08
Hey, I'm using neither Deadrat/Fedora nor SuSE at all :-)
I'm mainly using Gentoo which has had this issue for one or two weeks until someone (/me) noticed and submitted a patch. It had been fixed within a few days and marked stable, so I can't complain.
Or (on smaller boxes) Debian which did not have any issues I noticed.
Slow reverse DNS lookups
Shadow Hawkins on Thursday, 18 March 2004 09:57:58
Hi Bernard,
Could you supply me with your patches?
Cheers,
Willem.
Slow reverse DNS lookups
Shadow Hawkins on Thursday, 18 March 2004 20:24:54
The bug had been filed in Gentoo's bugzilla
http://bugs.gentoo.org/show_bug.cgi?id=42492
patch is included there.
Slow reverse DNS lookups
Shadow Hawkins on Friday, 26 March 2004 16:07:44
Been playing with fedora 1.90 (development) ... It now correctly resolves reverse DNS queries.
|
![[ch]](/s/countries/ch.gif)
on Wednesday, 17 March 2004 12:28:13
Posting is only allowed when you are