Sometimes users get host unknown
Peter Dambier
peter at peter-dambier.de
Tue Jun 13 13:30:34 UTC 2006
Looking at www.londonknowledge.ac.uk
it does not find londonknowledge.ac.uk either:
; <<>> DiG 9.1.3 <<>> -t any londonknowledge.ac.uk @lomi
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 27850
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0
;; QUESTION SECTION:
;londonknowledge.ac.uk. IN ANY
;; AUTHORITY SECTION:
ac.uk. 600 IN SOA ns0.ja.net. jips-nosc.nosc.ja.net. 2006061260 28800 7200 3600000 14400
;; Query time: 122 msec
;; SERVER: 192.168.48.227#53(lomi)
;; WHEN: Tue Jun 13 15:11:07 2006
;; MSG SIZE rcvd: 100
This one looks good to start with:
; <<>> DiG 9.1.3 <<>> -t any ac.uk @lomi
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 22184
;; flags: qr rd ra; QUERY: 1, ANSWER: 11, AUTHORITY: 8, ADDITIONAL: 4
;; QUESTION SECTION:
;ac.uk. IN ANY
;; ANSWER SECTION:
ac.uk. 86400 IN MX 2 kryten.ja.net.
ac.uk. 86400 IN MX 1 rimmer.ja.net.
ac.uk. 86400 IN SOA ns0.ja.net. jips-nosc.nosc.ja.net. 2006061260 28800 7200 3600000 14400
ac.uk. 86400 IN NS ns4.ja.net.
ac.uk. 86400 IN NS ns3.ja.net.
ac.uk. 86400 IN NS ns1.cs.ucl.ac.uk.
ac.uk. 86400 IN NS sunic.sunet.se.
ac.uk. 86400 IN NS ns.uu.net.
ac.uk. 86400 IN NS ns0.ja.net.
ac.uk. 86400 IN NS ws-fra1.win-ip.dfn.de.
ac.uk. 86400 IN NS ns2.ja.net.
;; AUTHORITY SECTION:
ac.uk. 86400 IN NS sunic.sunet.se.
ac.uk. 86400 IN NS ws-fra1.win-ip.dfn.de.
ac.uk. 86400 IN NS ns.uu.net.
ac.uk. 86400 IN NS ns1.cs.ucl.ac.uk.
ac.uk. 86400 IN NS ns4.ja.net.
ac.uk. 86400 IN NS ns2.ja.net.
ac.uk. 86400 IN NS ns3.ja.net.
ac.uk. 86400 IN NS ns0.ja.net.
;; ADDITIONAL SECTION:
ns2.ja.net. 114842 IN A 193.63.105.17
ns3.ja.net. 114842 IN A 193.63.106.103
ns4.ja.net. 114842 IN A 193.62.157.66
ws-fra1.win-ip.dfn.de. 3605 IN A 193.174.75.178
;; Query time: 248 msec
;; SERVER: 192.168.48.227#53(lomi)
;; WHEN: Tue Jun 13 15:14:34 2006
;; MSG SIZE rcvd: 482
Information seems the same on all servers:
soa("ac.uk","2006061260","sunic.sunet.se.","192.36.125.2").
soa("ac.uk","2006061260","ws-fra1.win-ip.dfn.de.","193.174.75.178").
soa("ac.uk","2006061260","ns.uu.net.","137.39.1.3").
soa("ac.uk","2006061260","ns4.ja.net.","193.62.157.66").
soa("ac.uk","2006061260","ns2.ja.net.","193.63.105.17").
soa("ac.uk","2006061260","ns3.ja.net.","193.63.106.103").
soa("ac.uk","2006061260","ns0.ja.net.","128.86.1.20").
soa("ac.uk","2006061260","ns0.ja.net.","193.63.94.20").
Let us try
; <<>> DiG 9.1.3 <<>> -t any ac.uk @ns0.ja.net
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 61722
;; flags: qr aa rd; QUERY: 1, ANSWER: 11, AUTHORITY: 0, ADDITIONAL: 9
;; QUESTION SECTION:
;ac.uk. IN ANY
;; ANSWER SECTION:
ac.uk. 86400 IN SOA ns0.ja.net. jips-nosc.nosc.ja.net. 2006061260 28800 7200 3600000 14400
ac.uk. 86400 IN NS sunic.sunet.se.
ac.uk. 86400 IN NS ws-fra1.win-ip.dfn.de.
ac.uk. 86400 IN NS ns.uu.net.
ac.uk. 86400 IN NS ns0.ja.net.
ac.uk. 86400 IN NS ns1.cs.ucl.ac.uk.
ac.uk. 86400 IN NS ns2.ja.net.
ac.uk. 86400 IN NS ns3.ja.net.
ac.uk. 86400 IN NS ns4.ja.net.
ac.uk. 86400 IN MX 2 kryten.ja.net.
ac.uk. 86400 IN MX 1 rimmer.ja.net.
;; ADDITIONAL SECTION:
ns0.ja.net. 86400 IN A 193.63.94.20
ns0.ja.net. 86400 IN A 128.86.1.20
ns0.ja.net. 86400 IN AAAA 2001:630:0:9::14
ns0.ja.net. 86400 IN AAAA 2001:630:0:8::14
ns1.cs.ucl.ac.uk. 360000 IN A 128.16.5.32
ns2.ja.net. 86400 IN A 193.63.105.17
ns2.ja.net. 86400 IN AAAA 2001:630:0:45::11
ns3.ja.net. 86400 IN A 193.63.106.103
ns3.ja.net. 86400 IN AAAA 2001:630:0:46::67
;; Query time: 86 msec
;; SERVER: 128.86.1.20#53(ns0.ja.net)
;; WHEN: Tue Jun 13 15:25:16 2006
;; MSG SIZE rcvd: 498
How about?
; <<>> DiG 9.1.3 <<>> -t any www.londonknowledge.ac.uk @ns0.ja.net
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 20363
;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0
;; QUESTION SECTION:
;www.londonknowledge.ac.uk. IN ANY
;; AUTHORITY SECTION:
ac.uk. 14400 IN SOA ns0.ja.net. jips-nosc.nosc.ja.net. 2006061260 28800 7200 3600000 14400
;; Query time: 79 msec
;; SERVER: 128.86.1.20#53(ns0.ja.net)
;; WHEN: Tue Jun 13 15:27:19 2006
;; MSG SIZE rcvd: 104
That is the bad guy
; <<>> DiG 9.1.3 <<>> -t any londonknowledge.ac.uk @ns0.ja.net
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 56892
;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0
;; QUESTION SECTION:
;londonknowledge.ac.uk. IN ANY
;; AUTHORITY SECTION:
ac.uk. 14400 IN SOA ns0.ja.net. jips-nosc.nosc.ja.net. 2006061260 28800 7200 3600000 14400
;; Query time: 80 msec
;; SERVER: 128.86.1.20#53(ns0.ja.net)
;; WHEN: Tue Jun 13 15:28:33 2006
;; MSG SIZE rcvd: 100
Hope that helps you
Kind regards
Peter and Karin Dambier
Peter Dambier wrote:
> Andrew Watkins wrote:
>
>>Hi,
>>
>>We have had an ongoing problem that some people (over the world) that
>>they can not access our web server, since they do not get an IP address.
>>
>>I have tested from my home ISP (away from work) and am unable to get the
>>same errors. I have tested the DNS from a few web sites www.dnsstuff.com
>>, etc and can not pin point any major problem
>>
>>Our webserver has many addresses
>>www.lkl.ac.uk
>>www.lonklab.ac.uk
>>www.londonknowledge.ac.uk
>>
>>
>>The last report we had from a user was: dig +trace +qr www.lkl.ac.uk
>>
>>; <<>> DiG 9.2.1 <<>> +trace +qr www.lkl.ac.uk
>>;; global options: printcmd
>>. 47891 IN NS c.root-servers.net.
>>. 47891 IN NS b.root-servers.net.
>>;; Received 356 bytes from 165.225.198.2#53(165.225.198.2) in 5 ms
>>
>>uk. 172800 IN NS NS1.NIC.uk.
>>uk. 172800 IN NS NSD.NIC.uk.
>>;; Received 493 bytes from 192.33.4.12#53(c.root-servers.net) in 48 ms
>>
>>ac.uk. 172800 IN NS ns1.cs.ucl.ac.uk.
>>ac.uk. 172800 IN NS ns2.ja.net.
>>ac.uk. 172800 IN NS ns3.ja.net.
>>ac.uk. 172800 IN NS ns4.ja.net.
>>ac.uk. 172800 IN NS sunic.sunet.se.
>>ac.uk. 172800 IN NS ws-fra1.win-ip.dfn.de.
>>ac.uk. 172800 IN NS ns.uu.net.
>>ac.uk. 172800 IN NS ns0.ja.net.
>>;; Received 233 bytes from 195.66.240.130#53(NS1.NIC.uk) in 129 ms
>>
>>lkl.ac.uk. 86400 IN NS ns1.lonklab.ac.uk.
>>lkl.ac.uk. 86400 IN NS mail1.ccs.bbk.ac.uk.
>>;; Received 101 bytes from 128.16.5.32#53(ns1.cs.ucl.ac.uk) in 150 ms
>>
>>dig: Couldn't find server 'ns1.lonklab.ac.uk': Name or service not known
>>
>>
>>Any pointers?
>>
>>
>>Thanks in advance,
>>
>>Andrew Watkins
>>*****************************************************************************
>>Unix Administrator tel: 020-7631 6720
>>Computer Science Department fax: 020-7631 6727
>>Birkbeck College (University of London)
>>Malet Street
>>London e-mail: andrew at dcs.bbk.ac.uk
>>WC1E 7HX
>>http://www.dcs.bbk.ac.uk/~andrew
>>*****************************************************************************
>>
>>
>
>
> Asking a djbdns resolver I get:
>
> ; <<>> DiG 9.1.3 <<>> -t any www.lkl.ac.uk @echnaton
> ;; global options: printcmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 21133
> ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0
>
> ;; QUESTION SECTION:
> ;www.lkl.ac.uk. IN ANY
>
> ;; ANSWER SECTION:
> www.lkl.ac.uk. 86400 IN CNAME thor.dcs.bbk.ac.uk.
> thor.dcs.bbk.ac.uk. 86400 IN A 193.61.29.33
>
> ;; Query time: 1663 msec
> ;; SERVER: 192.168.208.228#53(echnaton)
> ;; WHEN: Tue Jun 13 14:01:53 2006
> ;; MSG SIZE rcvd: 74
>
> 1 2/3 seconds to answer is not very fast.
>
>
> Asking a Bind 9.4.0 I get:
>
> ; <<>> DiG 9.1.3 <<>> -t any www.lkl.ac.uk @lomi
> ;; global options: printcmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 44818
> ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 1
>
> ;; QUESTION SECTION:
> ;www.lkl.ac.uk. IN ANY
>
> ;; ANSWER SECTION:
> www.lkl.ac.uk. 85585 IN CNAME thor.dcs.bbk.ac.uk.
>
> ;; AUTHORITY SECTION:
> lkl.ac.uk. 85585 IN NS ns1.lonklab.ac.uk.
> lkl.ac.uk. 85585 IN NS mail1.ccs.bbk.ac.uk.
>
> ;; ADDITIONAL SECTION:
> ns1.lonklab.ac.uk. 85994 IN A 193.61.29.32
>
> ;; Query time: 28 msec
> ;; SERVER: 192.168.48.227#53(lomi)
> ;; WHEN: Tue Jun 13 14:07:24 2006
> ;; MSG SIZE rcvd: 124
>
>
> but a CNAME is not an ip-address. I have to ask again:
>
> ; <<>> DiG 9.1.3 <<>> -t any thor.dcs.bbk.ac.uk @lomi
> ;; global options: printcmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 38786
> ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 3, ADDITIONAL: 4
>
> ;; QUESTION SECTION:
> ;thor.dcs.bbk.ac.uk. IN ANY
>
> ;; ANSWER SECTION:
> thor.dcs.bbk.ac.uk. 85421 IN A 193.61.29.33
>
> ;; AUTHORITY SECTION:
> bbk.ac.uk. 359021 IN NS bas-a.bcc.ac.uk.
> bbk.ac.uk. 359021 IN NS link-1.ts.bcc.ac.uk.
> bbk.ac.uk. 359021 IN NS ns0.ja.net.
>
> ;; ADDITIONAL SECTION:
> ns0.ja.net. 118707 IN A 193.63.94.20
> ns0.ja.net. 118707 IN A 128.86.1.20
> ns0.ja.net. 118707 IN AAAA 2001:630:0:9::14
> ns0.ja.net. 118707 IN AAAA 2001:630:0:8::14
>
> ;; Query time: 48 msec
> ;; SERVER: 192.168.48.227#53(lomi)
> ;; WHEN: Tue Jun 13 14:10:09 2006
> ;; MSG SIZE rcvd: 212
>
>
> Maybe some resolvers dont follow the CNAME. That may depend on
> what information is currently stored in their cache.
>
>
> Next test
>
> ; <<>> DiG 9.1.3 <<>> -t any www.londonknowledge.ac.uk @echnaton
> ;; global options: printcmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 43951
> ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0
>
> ;; QUESTION SECTION:
> ;www.londonknowledge.ac.uk. IN ANY
>
> ;; Query time: 137 msec
> ;; SERVER: 192.168.208.228#53(echnaton)
> ;; WHEN: Tue Jun 13 14:35:26 2006
> ;; MSG SIZE rcvd: 43
>
>
> After only 137 djbdns returns without an ip-address without a nameserver
>
>
> ; <<>> DiG 9.1.3 <<>> -t any www.londonknowledge.ac.uk @lomi
> ;; global options: printcmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 17733
> ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0
>
> ;; QUESTION SECTION:
> ;www.londonknowledge.ac.uk. IN ANY
>
> ;; AUTHORITY SECTION:
> ac.uk. 600 IN SOA ns0.ja.net. jips-nosc.nosc.ja.net. 2006061260 28800 7200 3600000 14400
>
> ;; Query time: 209 msec
> ;; SERVER: 192.168.48.227#53(lomi)
> ;; WHEN: Tue Jun 13 14:38:04 2006
> ;; MSG SIZE rcvd: 104
>
>
> Bind 9.4.0 has found the authority but not an answer.
>
--
Peter and Karin Dambier
Cesidian Root - Radice Cesidiana
Graeffstrasse 14
D-64646 Heppenheim
+49(6252)671-788 (Telekom)
+49(179)108-3978 (O2 Genion)
+49(6252)750-308 (VoIP: sipgate.de)
mail: peter at peter-dambier.de
mail: peter at echnaton.serveftp.com
http://iason.site.voila.fr/
https://sourceforge.net/projects/iason/
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