DNS resolution question

Casey Scott casey at scottmail.org
Wed Dec 24 14:40:47 UTC 2014


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



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