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DNS lookup issue

Hi All,

I have built five new servers that need to lookup against two DNS server.  One internal and the other external.

This worked fine for a week or so.  but recently it stops doing external lookups every 12 hours.  To fix it have either do an ipconfig/flushdns or run a repair on the NIC

Any idea how i can check to see what the issue is?
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detox1978
Asked:
detox1978
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1 Solution
 
subhashchyCommented:
have you try rebooting it once
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JamesSenior Cloud Infrastructure EngineerCommented:
Are you using Root Hints or DNS forwarding?
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yo_beeDirector of Information TechnologyCommented:
Do the Event Log report any errors or warnings on either side?

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detox1978Author Commented:
subhashchy, after rebooting the issue still reoccurs.

JBond2010, the external DNS servers has root hints, there are no forwarders setup.

yo_bee, there is nothing in the event logs to event suggest there is an issue.  If I PING a domains it returns not found.
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yo_beeDirector of Information TechnologyCommented:
Internal --> external or vice-versa ?
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detox1978Author Commented:
Also, when the issue is happening i can still do nslookups against the DNS server.
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JamesSenior Cloud Infrastructure EngineerCommented:
Do you think there may be a corrupt entry somewhere in DNS causing the issue? Do you have scavenaging turned on for stall records?
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JamesSenior Cloud Infrastructure EngineerCommented:
Have you check the host file on the server or servers to make sure there are no invalid static entries? And are the servers using the correct ip addresses for DNS resolution ie, are the server pointing to themselves locally?
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detox1978Author Commented:
yo_bee,  all the servers have three NICs.  1st External, 2nd Internal, 3rd management/back vLAN.  The order if the DNS on the external NIC is external, internal, external, internal.  The internal NIC has only internal DNS.  And the management/back vLAN has no DNS.

JBond2010, is there a way to check for a corupt entry?  +there are no invalid static entries, could this cause external DNS to stop occurring?  ++Yes the servers are pointing at themself.

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yo_beeDirector of Information TechnologyCommented:
Do they have different internal / external FQDN?
Also what is  the purpose of your external dns server?
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detox1978Author Commented:
The external is in a workgroup and internal on the domain.

The Internal DNS server doesn't have root hints, so the external was setup.
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yo_beeDirector of Information TechnologyCommented:
Did you apply delegation for the two zones?
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detox1978Author Commented:
The External is in a workgroup so i doubt there is any crossover.

How do i check?

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yo_beeDirector of Information TechnologyCommented:
Did you apply delegation for the two zones?
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yo_beeDirector of Information TechnologyCommented:
So your workgroup needs to see domain objects?
There has to be some sort of trust for the replication?
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detox1978Author Commented:
There is nothing that replicates.  The external DNS server is only used for lookups
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yo_beeDirector of Information TechnologyCommented:
I think I am missing something.
Sorry about this.
The workgroup has a DNS server with it's own subnet?
The domain also has it's own DNS for the domain?
What is your purpose of the dns in the workgroup (for Internet resolution or the internal domain resolution)?
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detox1978Author Commented:
The external DNS is not on its own subnet.   And is the only method for external DNS lookups.  Only the proxy and exchange server use it.
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yo_beeDirector of Information TechnologyCommented:
I would try what @JBond2010 suggested and create a forwarder.
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detox1978Author Commented:
Thanks for the tips.  we are setting up forwarding.
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