DNS Host Record - Static IP Changes in DNS to DHCP IP
We have an interesting DNS issue on a Windows 2003 domain running AD. We have a web server set with a static IP address. The host address of the web server is initially set in DNS mapped to the static address. What happens is (for some reason) that host address changes in DNS from the static IP address to another IP address (an address distributed by the DHCP server).
Now when you do a ping, for example, DNS resolves the web server name with the incorrect DHCP address. I can still ping the original static address, but for some reason the DNS gets changed and no longer resolves to the correct IP… I can manually change the host in DNS (on the DNS server) back to the static address, but this process continuously repeats and the static map in DNS changes to the same DHCP address. I’ve manually deleted the bogus DHCP address mapping from the DHCP server too.
Like I said the NIC is set to static, to the best of my knowledge there are no other devices on the network with that name, and I haven’t had any IP conflicts.
At this point I’m not sure what else it can be, so I’m posting here.
Now when you do a ping, for example, DNS resolves the web server name with the incorrect DHCP address. I can still ping the original static address, but for some reason the DNS gets changed and no longer resolves to the correct IP… I can manually change the host in DNS (on the DNS server) back to the static address, but this process continuously repeats and the static map in DNS changes to the same DHCP address. I’ve manually deleted the bogus DHCP address mapping from the DHCP server too.
Like I said the NIC is set to static, to the best of my knowledge there are no other devices on the network with that name, and I haven’t had any IP conflicts.
At this point I’m not sure what else it can be, so I’m posting here.
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Any other services on that machine (like VPN) that would assign another IP?
Can you find out what does this incorrect IP points to.
Does it pings. If the incorrect IP pings, then try and find which machine is doing it.
One more thing, you can try is to look the mac address of the machine in DHCP lease. See which MAC address has been assigned that incorrect IP address.
Does it pings. If the incorrect IP pings, then try and find which machine is doing it.
One more thing, you can try is to look the mac address of the machine in DHCP lease. See which MAC address has been assigned that incorrect IP address.
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ASKER
Neither VPN connections are installed, nor are RRAS services enabled or running.
When DNS picks up the record with the incorrect DHCP address of the web server, ping does not reply.
Even when the static DNS record exists, the DHCP address that the DNS eventually picks up in DNS does not ping.
When DNS picks up the record with the incorrect DHCP address of the web server, ping does not reply.
Even when the static DNS record exists, the DHCP address that the DNS eventually picks up in DNS does not ping.
Set up your DNS server for Secure Updates only.
This would prevent any rogue system from polluting your DNS.
This would prevent any rogue system from polluting your DNS.
When the incorrect IP is picked up, try running a reverse DNS query. On command prompt, type ping -a <ip address> and pass the results to us, please. The results should have a name such as computername.domain..
Please advise when you have captured the MAC address and given it a DHCP reservation.
Regards,
Imtiaz
Please advise when you have captured the MAC address and given it a DHCP reservation.
Regards,
Imtiaz
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ASKER
Not exactly sure which one of these fixed the problem, but this is no longer an issue. I'm just going to split the points for all who participated...
ASKER
I assisted the wrong answer for prashsax... The assist should go to this post:
Set up your DNS server for Secure Updates only.
This would prevent any rogue system from polluting your DNS.
If one of the forum mods would fix this, I apologize for the confusion. Thanks for all your help!
Set up your DNS server for Secure Updates only.
This would prevent any rogue system from polluting your DNS.
If one of the forum mods would fix this, I apologize for the confusion. Thanks for all your help!
ASKER
There is only 1 IP address there.
There are two network cards, but only 1 is plugged in and enabled.