I manage a VPS which hosts a forum and recently we migrated from one physical VPS host to another in the same company, with a downtime of about 48h and all configuration was made with cpanel
full account backups.
Since then, our users reported intermittent DNS failures. Most of them report things like normal behaviour from midnight until noon and DNS failures from noon to midnight. They are also under corporate networks and are unable to change their DNS server settings. (And I also believe that solving this kind of problems by suggesting client-side settings changes isn't an elegant solution for a large-ish website)
One of the moderators is experiencing this kind of error and sent me the following dig
output:
; <<>> DiG 9.7.0-P1 <<>> clubecetico.org
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 56625
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 4, ADDITIONAL: 4
;; QUESTION SECTION:
;clubecetico.org. IN A
;; ANSWER SECTION:
clubecetico.org. 7246 IN A 193.164.133.22
;; AUTHORITY SECTION:
clubecetico.org. 70536 IN NS ns2.ns-serve.net.
clubecetico.org. 70536 IN NS ns1.ns-serve.net.
clubecetico.org. 70536 IN NS ns2.ns-service.de.
clubecetico.org. 70536 IN NS ns.ns-service.de.
;; ADDITIONAL SECTION:
ns.ns-service.de. 82917 IN A 194.126.239.242
ns1.ns-serve.net. 56831 IN A 193.254.189.162
ns2.ns-serve.net. 56831 IN A 83.243.59.34
ns2.ns-service.de. 82917 IN A 213.203.228.195
;; Query time: 744 msec
;; SERVER: 200.198.34.81#53(200.198.34.81)
;; WHEN: Fri Sep 20 16:20:53 2013
;; MSG SIZE rcvd: 209
Here, using google's 8.8.8.8
and 8.8.4.4
the error never occurs and the output is
; <<>> DiG 9.9.3-P2 <<>> clubecetico.org
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 8975
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 3
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1280
;; QUESTION SECTION:
;clubecetico.org. IN A
;; ANSWER SECTION:
clubecetico.org. 11061 IN A 193.164.133.22
;; AUTHORITY SECTION:
clubecetico.org. 34589 IN NS ns1.clubecetico.org.
clubecetico.org. 34589 IN NS ns2.clubecetico.org.
;; ADDITIONAL SECTION:
ns1.clubecetico.org. 19614 IN A 193.164.133.22
ns2.clubecetico.org. 34589 IN A 193.164.133.22
;; Query time: 16 msec
;; SERVER: 192.168.1.1#53(192.168.1.1)
;; WHEN: Sat Sep 28 13:56:36 BRT 2013
;; MSG SIZE rcvd: 128
The only DNS configuration I have access to is that the nameservers I should use are ns1.clubecetico.org
and ns2.clubecetico.org. In the
cpanel` DNS setup, I added an A record with the server's IP.
But I really think that there's something missing because I'm not sure if the DNS client can query ns1.clubecetico.org
to obtain the IP of clubecetico.org
.
I also have no idea where these ns-service.net
come from and why some DNS servers reply with them.
Is there any server-side thing I can do about this issue? Why do these servers reply so differently?
Thanks in advance