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PING resolves to old IP address

Hello
I have DHCP and DNS enabled on my network.
Today when i ping a machine by name it is returning a completly different IP than the one the machine is using as it got a new IP this morning.
How long does it take DNS to update and refresh?
Can i force a refresh?

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Seanie_
Asked:
Seanie_
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1 Solution
 
Britt ThompsonSr. Systems EngineerCommented:
forcing a refresh on a windows machine is done like this:

Goto Start > Run > type CMD > and type > ipconfig /flushdns

Also, if it's an Active Directory integrated domain there may be a cached DNS record. You can also run

ipconfig /registerdns or simply right click on the network connection itself and run a repair and it will do all this for you.
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Seanie_Author Commented:
sorry its all active directory intergrated.

I thought DNS checked every hour for and updates to itself?
I am aware of /flushdns on the clients but these entries come from my DNS servers?
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cmorffewCommented:
Any changes to your DNS server will be instant on the network, however the workstations will hold a cache of previously contacted machines.  you will need to run the /flushdns options as mentioned by renazonse to clear the cache on the workstation.

Check to make sure that your DNS server has the correct IP address - if not you can always manually update it.
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Britt ThompsonSr. Systems EngineerCommented:
Exactly, the clients will hold on to the old cache for quite some time. The network adapter repair option will flush everything.
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Seanie_Author Commented:
i have used the flush dns comand on the dns server and clients and still the name resolves to a incorrect ip address.

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Britt ThompsonSr. Systems EngineerCommented:
Is it pinging with the incorrect IP from the server? This may be a stupid question but have you flushed the DNS on the machine you're pinging from? Also, if you have access to the DNS server I'd verify that the record is updated in DNS management.
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cmorffewCommented:
have you checked the DNS server for the machine entry? - you will need to make sure that the entry is correct.
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Seanie_Author Commented:
from the server it resolves to the incorrect IP also. and then destination host unreachable against the DNS server.

Pinging computer name [172.17.10.110] with 32 bytes of data:
Reply from 172.17.10.230: Destination host unreachable.
Reply from 172.17.10.230: Destination host unreachable.
Reply from 172.17.10.230: Destination host unreachable.
Reply from 172.17.10.230: Destination host unreachable.

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Seanie_Author Commented:
the record is there in the forward lookup zone and reverse lookup zone.
do these entries not delete after a time? and need to be refreshed
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Britt ThompsonSr. Systems EngineerCommented:
Have you run the repair on the network connection of the problem machine? This will re-register the dns and adjust the entries on the DNS server, assuming the machine is a domain member.

Does this machine have 2 network cards? Hard wired and wireless perhaps? Deleting the entries in DNS will not hurt anything if you want to delete them then run a repair on the network adapter of the machine in question.
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Seanie_Author Commented:
hi tehre i have not run repair on the network card as yet.
i can see that on the DNS servers the aging setting is 7 days.
Shoudl this be less
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Britt ThompsonSr. Systems EngineerCommented:
The aging shouldn't matter...if the machine pulls and IP and re-registers with DNS this will change immediately regardless. If you run the repair it will run the DNS registration and update the records. Also, a reboot may do the trick as well.
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Seanie_Author Commented:
ah yes thank you a repair has fixed the problem.
Thanks so much
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