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From tcpdump:

Sep 12 23:03:43 server named[25095]: error (unexpected RCODE SERVFAIL) resolving '': ip#53

OS: CentOS 6 resolv.conf


Using Bind with recursion in options off No firewall on Hosts file is normal


; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.10.rc1.el6_3.2 <<>> @localhost
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 57512
;; flags: qr rd ra; QUERY: 1, ANSWER: 6, AUTHORITY: 4, ADDITIONAL: 4

;                    IN      A

;; ANSWER SECTION:             300     IN      A             300     IN      A             300     IN      A             300     IN      A             300     IN      A             300     IN      A

;; AUTHORITY SECTION:             172131  IN      NS             172131  IN      NS             172131  IN      NS             172131  IN      NS

;; ADDITIONAL SECTION:         172131  IN      A         172131  IN      A         172131  IN      A         172131  IN      A

;; Query time: 18 msec
;; WHEN: Thu Sep 13 00:23:16 2012
;; MSG SIZE  rcvd: 260

p.s. can't even access site with domain anymore.

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What is the question here ? – topdog Sep 13 '12 at 4:17
The question is why is it doing this? I know this isn't normal behavior. I can resolve domain names to IP addresses but I cannot ping domains or IP addreses. I also get constant servfails in tcpdump although people are able to connect to my site and interact with it as usual. – Tar Sep 13 '12 at 4:24
Well the question does not provide any indication of your environment, can you edit it to provide more detail – topdog Sep 13 '12 at 4:29
I've edited with some more information.. though I don't know how to format it. – Tar Sep 13 '12 at 4:32
Drop the two google nameservers from resolv.conf and add them as forwarders in /etc/named.conf instead. – topdog Sep 13 '12 at 4:37

If you are asking why it is trying to resolv instead of, then the answer is probably IS trying to resolve failing and then using the search path you have defined in your resolv.conf in the line search

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It really is hard to know what you're asking but I'll give it a shot. You have set as your first nameserver, so that's what is checked first.

With recursion turned off a DNS request that cannot be authouritatively answered by the localhost will get a SERVFAIL, which is still an answer. That is the end of the story. The other nameservers should not be consulted because you already have an answer. They will only be consulted if fails to respond to the query.

With recursion turned on for the same query the local instance of BIND will recurse and try to get you a valid answer. If the local instance responds in any way the other nameservers will not be consulted.

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