DNS resolution question
Casey Scott
casey at scottmail.org
Thu Dec 25 16:30:13 UTC 2014
This turned out to be a firewall problem. The rule permitting DNS traffic wasn't stateful. Adding a --keep-state solved the problem (allow udp from any to any dst-port 53 keep-state).
Thanks for the help!
Casey
----- On Dec 25, 2014, at 7:43 AM, Casey Scott casey at scottmail.org wrote:
> Another piece of data:
>
> When the server in question is pointed to another server for DNS resolution
> (/etc/resolv.conf), the bind-utils (host/nslookup) can successfully lookup the
> same records. That machine is running Centos 6.6. Its named -V
>
> BIND 9.8.2rc1-RedHat-9.8.2-0.30.rc1.el6_6.1 built with
> '--build=x86_64-redhat-linux-gnu' '--host=x86_64-redhat-linux-gnu'
> '--target=x86_64-redhat-linux-gnu' '--program-prefix=' '--prefix=/usr'
> '--exec-prefix=/usr' '--bindir=/usr/bin' '--sbindir=/usr/sbin'
> '--sysconfdir=/etc' '--datadir=/usr/share' '--includedir=/usr/include'
> '--libdir=/usr/lib64' '--libexecdir=/usr/libexec' '--sharedstatedir=/var/lib'
> '--mandir=/usr/share/man' '--infodir=/usr/share/info' '--with-libtool'
> '--localstatedir=/var' '--enable-threads' '--enable-ipv6'
> '--enable-filter-aaaa' '--with-pic' '--disable-static'
> '--disable-openssl-version-check' '--with-dlopen=yes' '--with-dlz-ldap=yes'
> '--with-dlz-postgres=yes' '--with-dlz-mysql=yes' '--with-dlz-filesystem=yes'
> '--with-gssapi=yes' '--disable-isc-spnego'
> '--with-docbook-xsl=/usr/share/sgml/docbook/xsl-stylesheets'
> '--enable-fixed-rrset' 'build_alias=x86_64-redhat-linux-gnu'
> 'host_alias=x86_64-redhat-linux-gnu' 'target_alias=x86_64-redhat-linux-gnu'
> 'CFLAGS= -O2 -g
> -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector
> --param=ssp-buffer-size=4 -m64 -mtune=generic' 'CPPFLAGS= -DDIG_SIGCHASE'
> using OpenSSL version: OpenSSL 1.0.1e 11 Feb 2013
> using libxml2 version: 2.7.6
>
> Noting that on the Linux server, IPv6 is enabled (though the server doesn't use
> IPv6), I recompiled BIND with IPv6 enabled. Same result though. I can not
> resolve vuxml.freebsd.org with it.
>
>
>
> ----- On Dec 25, 2014, at 7:03 AM, Casey Scott casey at scottmail.org wrote:
>
>> named -V output includes '--disable-ipv6'. Isn't that explicitly disabling IPv6?
>>
>> Thanks.
>>
>> ----- On Dec 24, 2014, at 1:57 PM, g lister g.lister at nodeunit.ch wrote:
>>
>>> On Wed Dec 24 22:09:26 2014 GMT+0100, Casey Scott wrote:
>>>> Ah.. well in that case, IPv6 is already disabled in named.
>>>
>>> Is it disabled explicitly? I mean by a directive. I had also disabled it ... By
>>> not enabling it but I had to disable it explicitly and then some queries coming
>>> from my internal network and my smtp started working. Problem is you need to
>>> have functioning IPv6 network setup to make use of it.
>>> Sorry for being short but writing on a phone is a pain. The syntax should be in
>>> a man page or the net.
>>>
>>> HTH,
>>> George
>>>
>>>>
>>>>
>>>> ----- On Dec 24, 2014, at 11:34 AM, g lister g.lister at nodeunit.ch wrote:
>>>>
>>>> > On Wed Dec 24 20:07:40 2014 GMT+0100, Casey Scott wrote:
>>>> >> I can't disable IPv4 because my environment uses it. Thanks though.
>>>> >
>>>> > Sorry I meant IPv6, AAAA are v6 querries I think.
>>>> >
>>>> >>
>>>> >> Casey
>>>> >>
>>>> >> ----- On Dec 24, 2014, at 10:10 AM, g lister g.lister at nodeunit.ch wrote:
>>>> >>
>>>> >> > On Wed Dec 24 18:57:42 2014 GMT+0100, Casey Scott wrote:
>>>> >> >> That's what's odd. The tcpdump shows a seemingly valid response comeback,
>>>> >> >> however dig/host always fail with a timeout. It seems to me that named isn't
>>>> >> >> passing along the response for some reason.
>>>> >> >>
>>>> >> >> Thanks.
>>>> >> >
>>>> >> >
>>>> >> > Have you tried disabling IPv4 and checking whether it works?
>>>> >> > I had a similiar issue with bind and without IPv4 it was OK.
>>>> >> >
>>>> >> > HTH,
>>>> >> > George
>>>> >> >
>>>> >> >>
>>>> >> >> ----- On Dec 24, 2014, at 8:31 AM, Bruce Ferrell bferrell at baywinds.org wrote:
>>>> >> >>
>>>> >> >> > On 12/24/2014 06:40 AM, Casey Scott wrote:
>>>> >> >> >> This issue surfaced when I noticed this entry in my servers daily security mail:
>>>> >> >> >>
>>>> >> >> >> Checking for packages with security vulnerabilities:
>>>> >> >> >> pkg: http://vuxml.freebsd.org/freebsd/vuln.xml.bz2: No address record
>>>> >> >> >> pkg: cannot fetch vulnxml file
>>>> >> >> >>
>>>> >> >> >>
>>>> >> >> >> I discovered that the server is not able to resolve vuxml.freebsd.org, or even
>>>> >> >> >> www.freebsd.org. I'm sure the problem isn't specific to the freebsd.org zone,
>>>> >> >> >> but that's where I focused my effort. I found that recursive queries failed,
>>>> >> >> >> however if I directly queried a name server authoritative for freebsd.org (i.e.
>>>> >> >> >> ns1.isc-sns.net.), the query successfully returned the CNAME.
>>>> >> >> >>
>>>> >> >> >> OS Details:
>>>> >> >> >> FreeBSD mustang 9.3-RELEASE FreeBSD 9.3-RELEASE #0 r271930: Sun Sep 21 19:01:57
>>>> >> >> >> PDT 2014 root at mustang:/usr/src/sys/amd64/compile/Server amd64
>>>> >> >> >>
>>>> >> >> >>
>>>> >> >> >> DNS lookup attempt
>>>> >> >> >> *******************************************************************************
>>>> >> >> >> $ dig vuxml.freebsd.org +trace
>>>> >> >> >> ; <<>> DiG 9.9.6-P1 <<>> vuxml.freebsd.org +trace
>>>> >> >> >> ;; global options: +cmd
>>>> >> >> >> . 517326 IN NS e.root-servers.net.
>>>> >> >> >> . 517326 IN NS m.root-servers.net.
>>>> >> >> >> . 517326 IN NS c.root-servers.net.
>>>> >> >> >> . 517326 IN NS d.root-servers.net.
>>>> >> >> >> . 517326 IN NS b.root-servers.net.
>>>> >> >> >> . 517326 IN NS f.root-servers.net.
>>>> >> >> >> . 517326 IN NS g.root-servers.net.
>>>> >> >> >> . 517326 IN NS i.root-servers.net.
>>>> >> >> >> . 517326 IN NS k.root-servers.net.
>>>> >> >> >> . 517326 IN NS l.root-servers.net.
>>>> >> >> >> . 517326 IN NS a.root-servers.net.
>>>> >> >> >> . 517326 IN NS j.root-servers.net.
>>>> >> >> >> . 517326 IN NS h.root-servers.net.
>>>> >> >> >> . 517326 IN RRSIG NS 8 0 518400 20141231050000
>>>> >> >> >> 20141224040000 22603 . OT3Uv0Krt43V999nh6ky8sK7Uob+Qb+M82BOS0uPTFxq1NL6m2XX7ri3
>>>> >> >> >> n/na4QyB/+iGTAlonAMVGyXEO1llrJt6iw7yucBriqy/xuGCwSY5Sllc
>>>> >> >> >> Y3G7RdzerNgmAhfD2wiCwJPnVuGaD3O5318r2TLrsXdoQwGk7FNWiE1X GBE=
>>>> >> >> >> ;; Received 913 bytes from 192.168.1.1#53(192.168.1.1) in 0 ms
>>>> >> >> >>
>>>> >> >> >> org. 172800 IN NS b2.org.afilias-nst.org.
>>>> >> >> >> org. 172800 IN NS a2.org.afilias-nst.info.
>>>> >> >> >> org. 172800 IN NS d0.org.afilias-nst.org.
>>>> >> >> >> org. 172800 IN NS b0.org.afilias-nst.org.
>>>> >> >> >> org. 172800 IN NS a0.org.afilias-nst.info.
>>>> >> >> >> org. 172800 IN NS c0.org.afilias-nst.info.
>>>> >> >> >> org. 86400 IN DS 21366 7 2
>>>> >> >> >> 96EEB2FFD9B00CD4694E78278B5EFDAB0A80446567B69F634DA078F0 D90F01BA
>>>> >> >> >> org. 86400 IN DS 21366 7 1
>>>> >> >> >> E6C1716CFB6BDC84E84CE1AB5510DAC69173B5B2
>>>> >> >> >> org. 86400 IN RRSIG DS 8 1 86400 20141231050000
>>>> >> >> >> 20141224040000 22603 . IjE3Yi3yF8a12dOlLt13Grqs7c2tOXwgyyghAkeqy36N14VrAGxsQMxU
>>>> >> >> >> RlOE5rYwzeg1cLi55wRxGShNBz0/KU229xWrRNluzLUkbo+eW98E6Fcw
>>>> >> >> >> nT/DHrIy9J/3zjf6NRC+zUUcQTOJGWAkPF40TqaJGwI0Ag6/p6yxcBJ5 MDM=
>>>> >> >> >> ;; Received 691 bytes from 192.112.36.4#53(g.root-servers.net) in 73 ms
>>>> >> >> >>
>>>> >> >> >> freebsd.org. 86400 IN NS ns2.isc-sns.com.
>>>> >> >> >> freebsd.org. 86400 IN NS ns1.isc-sns.net.
>>>> >> >> >> freebsd.org. 86400 IN NS ns3.isc-sns.info.
>>>> >> >> >> freebsd.org. 86400 IN DS 32659 8 2
>>>> >> >> >> AF3B32E46DF2FC32C0110C7D6B808EE73E0411501AFAF9022D3DCD0A FA5B3ACD
>>>> >> >> >> freebsd.org. 86400 IN RRSIG DS 7 2 86400 20150109163356
>>>> >> >> >> 20141219153356 11112 org.
>>>> >> >> >> puF07NdtGtOY0uI3d789itchA2dEXz0URwCsckm7vjWoNIhdsMuG6jFc
>>>> >> >> >> StzdAkvFDiDO/2C3x21spRrb7Y3ioDQpNJL2zJUn2S0L/8ueDbF9wJAT
>>>> >> >> >> pEfAdMyUwlCQkVM45Ptf98z7iLTWWe2xQBhZZ1OGaPRW+VwKE0rCaz2d 1rg=
>>>> >> >> >> ;; Received 345 bytes from 199.19.53.1#53(c0.org.afilias-nst.info) in 134 ms
>>>> >> >> >>
>>>> >> >> >> ;; connection timed out; no servers could be reached
>>>> >> >> >> *******************************************************************************
>>>> >> >> >>
>>>> >> >> >>
>>>> >> >> >> tcpdump of the query above
>>>> >> >> >> *******************************************************************************
>>>> >> >> >> listening on fxp0, link-type EN10MB (Ethernet), capture size 65535 bytes
>>>> >> >> >> 05:59:36.016640 IP x.x.x.x.54272 > 38.103.2.1.53: 18640 [1au] A?
>>>> >> >> >> vuxml.freebsd.org. (46)
>>>> >> >> >> 05:59:36.127776 IP 38.103.2.1.53 > x.x.x.x.54272: 18640*- 4/4/11 CNAME
>>>> >> >> >> wfe0.ysv.freebsd.org., RRSIG, A 8.8.178.110, RRSIG (1464)
>>>> >> >> >> 05:59:38.021067 IP x.x.x.x.52431 > 38.103.2.1.53: 13086 [1au] AAAA?
>>>> >> >> >> vuxml.freebsd.org. (46)
>>>> >> >> >> 05:59:38.051272 IP x.x.x.x.51125 > 63.243.194.1.53: 16824 [1au] A?
>>>> >> >> >> vuxml.freebsd.org. (46)
>>>> >> >> >> 05:59:38.081819 IP 63.243.194.1.53 > x.x.x.x.51125: 16824*- 4/4/11 CNAME
>>>> >> >> >> wfe0.ysv.freebsd.org., RRSIG, A 8.8.178.110, RRSIG (1464)
>>>> >> >> >> 05:59:38.132821 IP 38.103.2.1.53 > x.x.x.x.52431: 13086*- 4/4/11 CNAME
>>>> >> >> >> wfe0.ysv.freebsd.org., RRSIG, AAAA, RRSIG (1464)
>>>> >> >> >> 05:59:40.056275 IP x.x.x.x.62003 > 63.243.194.1.53: 41954 [1au] AAAA?
>>>> >> >> >> vuxml.freebsd.org. (46)
>>>> >> >> >> 05:59:40.086597 IP 63.243.194.1.53 > x.x.x.x.62003: 41954*- 4/4/11 CNAME
>>>> >> >> >> wfe0.ysv.freebsd.org., RRSIG, AAAA, RRSIG (1464)
>>>> >> >> >> 05:59:40.267272 IP x.x.x.x.61416 > 72.52.71.1.53: 32843 [1au] A?
>>>> >> >> >> vuxml.freebsd.org. (46)
>>>> >> >> >> 05:59:40.297103 IP 72.52.71.1.53 > x.x.x.x.61416: 32843*- 4/4/11 CNAME
>>>> >> >> >> wfe0.ysv.freebsd.org., RRSIG, A 8.8.178.110, RRSIG (1464)
>>>> >> >> >> 05:59:42.272273 IP x.x.x.x.54674 > 72.52.71.1.53: 2755 [1au] AAAA?
>>>> >> >> >> vuxml.freebsd.org. (46)
>>>> >> >> >> 05:59:42.302289 IP 72.52.71.1.53 > x.x.x.x.54674: 2755*- 4/4/11 CNAME
>>>> >> >> >> wfe0.ysv.freebsd.org., RRSIG, AAAA, RRSIG (1464)
>>>> >> >> >> 05:59:42.487277 IP x.x.x.x.54239 > 38.103.2.1.53: 38272 [1au] A?
>>>> >> >> >> vuxml.freebsd.org. (46)
>>>> >> >> >> 05:59:42.598927 IP 38.103.2.1.53 > x.x.x.x.54239: 38272*- 4/4/11 CNAME
>>>> >> >> >> wfe0.ysv.freebsd.org., RRSIG, A 8.8.178.110, RRSIG (1464)
>>>> >> >> >> 05:59:44.492281 IP x.x.x.x.59505 > 38.103.2.1.53: 22873 [1au] AAAA?
>>>> >> >> >> vuxml.freebsd.org. (46)
>>>> >> >> >> 05:59:44.604217 IP 38.103.2.1.53 > x.x.x.x.59505: 22873*- 4/4/11 CNAME
>>>> >> >> >> wfe0.ysv.freebsd.org., RRSIG, AAAA, RRSIG (1464)
>>>> >> >> >> 05:59:44.722266 IP x.x.x.x.61141 > 63.243.194.1.53: 50828 [1au] A?
>>>> >> >> >> vuxml.freebsd.org. (46)
>>>> >> >> >> 05:59:44.753517 IP 63.243.194.1.53 > x.x.x.x.61141: 50828*- 4/4/11 CNAME
>>>> >> >> >> wfe0.ysv.freebsd.org., RRSIG, A 8.8.178.110, RRSIG (1464)
>>>> >> >> >> 05:59:46.727324 IP x.x.x.x.49803 > 63.243.194.1.53: 51222 [1au] AAAA?
>>>> >> >> >> vuxml.freebsd.org. (46)
>>>> >> >> >> 05:59:46.757577 IP 63.243.194.1.53 > x.x.x.x.49803: 51222*- 4/4/11 CNAME
>>>> >> >> >> wfe0.ysv.freebsd.org., RRSIG, AAAA, RRSIG (1464)
>>>> >> >> >> 05:59:57.395692 IP x.x.x.x.60149 > 165.254.1.208.53: 31873 [1au] A?
>>>> >> >> >> e6238.a.akamaiedge.net. (51)
>>>> >> >> >> 05:59:57.404644 IP 165.254.1.208.53 > x.x.x.x.60149: 31873*- 1/0/0 A 96.7.67.53
>>>> >> >> >> (56)
>>>> >> >> >> *******************************************************************************
>>>> >> >> >>
>>>> >> >> >> BIND build options
>>>> >> >> >> *******************************************************************************
>>>> >> >> >> # named -V
>>>> >> >> >> BIND 9.9.6-P1 (Extended Support Version) <id:3612d8fb> built by make with
>>>> >> >> >> '--localstatedir=/var' '--disable-linux-caps' '--disable-symtable'
>>>> >> >> >> '--with-randomdev=/dev/random' '--with-libxml2=/usr/local'
>>>> >> >> >> '--disable-filter-aaaa' '--disable-fixed-rrset' '--without-gost'
>>>> >> >> >> '--without-idn' '--disable-ipv6' '--disable-largefile' '--disable-newstats'
>>>> >> >> >> '--without-python' '--disable-rpz-nsdname' '--disable-rpz-nsip' '--disable-rrl'
>>>> >> >> >> '--with-openssl=/usr/local' '--without-gssapi' '--enable-threads'
>>>> >> >> >> '--sysconfdir=/etc/namedb' '--prefix=/usr' '--mandir=/usr/share/man'
>>>> >> >> >> '--infodir=/usr/share/info/' '--build=amd64-portbld-freebsd9.3'
>>>> >> >> >> 'build_alias=amd64-portbld-freebsd9.3' 'CC=cc' 'CFLAGS=-O2 -pipe -march=native
>>>> >> >> >> -fstack-protector -fno-strict-aliasing' 'LDFLAGS= -Wl,-rpath,/usr/local/lib
>>>> >> >> >> -fstack-protector' 'LIBS=' 'CPPFLAGS=' 'CPP=cpp'
>>>> >> >> >> compiled by GCC 4.2.1 20070831 patched [FreeBSD]
>>>> >> >> >> using OpenSSL version: OpenSSL 1.0.1j 15 Oct 2014
>>>> >> >> >> using libxml2 version: 2.9.2
>>>> >> >> >> *******************************************************************************
>>>> >> >> >>
>>>> >> >> >> Any idea what's going on here?
>>>> >> >> >>
>>>> >> >> >> Thanks,
>>>> >> >> >> Casey
>>>> >> >> >>
>>>> >> >> >> _______________________________________________
>>>> >> >> >> freebsd-questions at freebsd.org mailing list
>>>> >> >> >> http://lists.freebsd.org/mailman/listinfo/freebsd-questions
>>>> >> >> >> To unsubscribe, send any mail to "freebsd-questions-unsubscribe at freebsd.org"
>>>> >> >> >>
>>>> >> >> > Casey,
>>>> >> >> >
>>>> >> >> > think you're getting a correct response.
>>>> >> >> > dig @192.0.2.131 vuxml.freebsd.org
>>>> >> >> >
>>>> >> >> > ; <<>> DiG 9.9.5-rpz2+rl.14038.05-P1 <<>> @192.0.2.131 vuxml.freebsd.org
>>>> >> >> > ; (1 server found)
>>>> >> >> > ;; global options: +cmd
>>>> >> >> > ;; Got answer:
>>>> >> >> > ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 54956
>>>> >> >> > ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 3, ADDITIONAL: 6
>>>> >> >> >
>>>> >> >> > ;; OPT PSEUDOSECTION:
>>>> >> >> > ; EDNS: version: 0, flags:; udp: 4096
>>>> >> >> > ;; QUESTION SECTION:
>>>> >> >> > ;vuxml.freebsd.org. IN A
>>>> >> >> >
>>>> >> >> > ;; ANSWER SECTION:
>>>> >> >> > vuxml.freebsd.org. 497 IN CNAME wfe0.ysv.freebsd.org.
>>>> >> >> > wfe0.ysv.freebsd.org. 497 IN A 8.8.178.110
>>>> >> >> >
>>>> >> >> > ;; AUTHORITY SECTION:
>>>> >> >> > freebsd.org. 497 IN NS ns3.isc-sns.info.
>>>> >> >> > freebsd.org. 497 IN NS ns2.isc-sns.com.
>>>> >> >> > freebsd.org. 497 IN NS ns1.isc-sns.net.
>>>> >> >> >
>>>> >> >> > ;; ADDITIONAL SECTION:
>>>> >> >> > ns1.isc-sns.net. 2488 IN A 72.52.71.1
>>>> >> >> > ns1.isc-sns.net. 166365 IN AAAA 2001:470:1a::1
>>>> >> >> > ns2.isc-sns.com. 2488 IN A 38.103.2.1
>>>> >> >> > ns3.isc-sns.info. 2488 IN A 63.243.194.1
>>>> >> >> > ns3.isc-sns.info. 79965 IN AAAA 2001:5a0:10::1
>>>> >> >> >
>>>> >> >> > ;; Query time: 1 msec
>>>> >> >> > ;; SERVER: 192.0.2.131#53(192.0.2.131)
>>>> >> >> > ;; WHEN: Wed Dec 24 08:28:06 PST 2014
>>>> >> >> > ;; MSG SIZE rcvd: 277
>>>> >> >> >
>>>> >> >> > Notice in the answer section of my simplified query via my local nameserver,
>>>> >> >> > wfe0.ysv.freebsd.org is in the A record. I saw the same response in your
>>>> >> >> > query, it was just harder to see.
>>>> >> >> >
>>>> >> >> >
>>>> >> >> > _______________________________________________
>>>> >> >> > freebsd-questions at freebsd.org mailing list
>>>> >> >> > http://lists.freebsd.org/mailman/listinfo/freebsd-questions
>>>> >> >> > To unsubscribe, send any mail to "freebsd-questions-unsubscribe at freebsd.org"
>>>> >> >> _______________________________________________
>>>> >> >> freebsd-questions at freebsd.org mailing list
>>>> >> >> http://lists.freebsd.org/mailman/listinfo/freebsd-questions
>>>> >> >> To unsubscribe, send any mail to "freebsd-questions-unsubscribe at freebsd.org"
>>>> >> >>
>>>> >> >
>>>> >> > --
>>>> >> _______________________________________________
>>>> >> freebsd-questions at freebsd.org mailing list
>>>> >> http://lists.freebsd.org/mailman/listinfo/freebsd-questions
>>>> >> To unsubscribe, send any mail to "freebsd-questions-unsubscribe at freebsd.org"
>>>> >>
>>>> >
>>>> > --
>>>>
>>>
>>> --
>> _______________________________________________
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>> To unsubscribe, send any mail to "freebsd-questions-unsubscribe at freebsd.org"
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