Help - duplicate workstation AD DNS records

Mal1ce

Well-Known Member
Joined
Feb 3, 2006
Messages
259
Hoping for some wisdom from some more experienced AD/DNS folks here on here.

My users with laptops are getting two A records in the forward DNS zone, one for their wireless cards and one for wired. They only get a single PTR record in the reverse DNS zone.

What appears to be happening is users are working at home, hibernating their notebooks, then coming into the office the next morning and opening the screen before plugging in their network cable.

As a result, the machine automatically connects to the wireless network first, gets an IP and DHCP registers an A record. Then when the network cable is plugged in, the machine gets another IP and DHCP registers another A record. DHCP seems to update the PTR record.

This is wreaking havoc with the Konica Minolta scan-to-PC FTP utility or connecting to these machines via hostname as I keep querying and getting the IP assigned to the wireless card from DNS and not the one assigned to the cabled Ethernet adapter.


i've configured an user account for DHCP with strong password, set DHCP to run using those credentials, added the DHCP server (which is also the DC) to the DnsUpdateProxy group & secured it and set DHCP to update everything.


How can I go about forcing DHCP to instead update the A record rather than register a second one when the laptops swap from wireless to wired?

Any advice appreciated!
 

ThatOtherDude

Well-Known Member
Joined
Sep 10, 2018
Messages
223
your setup is normal.

(having users randomly connect / disconnect wifi & wired in a AD + DHCP environment)

check your DHCP server settings though.
enable the checkbox - Automatically update DHCP client information in DNS
enable the checkbox - Enable updates for DNS clients that do not support dynamic updates




also, I don't actually understand your issue.

regardless of whether your laptops are connected to wired or wifi (or both), your Konica MFP should be able to connect to the laptop (using the laptop's FQDN) as long as AT LEAST one of the two connections are active.


You didn't fully explain what the issue is.



but, for my own sanity I would (if I was you):

configure the wifi LAN as subnet A with DHCP pool A.
configure wired LAN as subnet B with DHCP pool B.
configure the Konica Minolta MFP to "scan-to-email" from an O365 or GMAIL account.

I wouldn't use FTP at all.

how does that work b.t.w?
do you have FTP Server running on each of your client PC's?
Is the Konica Minolta the "FTP client" that copies files to the laptop?

that sounds seriously old-school....
 

DMNknight

Expert Member
Joined
Oct 17, 2003
Messages
3,193
Hoping for some wisdom from some more experienced AD/DNS folks here on here.

My users with laptops are getting two A records in the forward DNS zone, one for their wireless cards and one for wired. They only get a single PTR record in the reverse DNS zone.

What appears to be happening is users are working at home, hibernating their notebooks, then coming into the office the next morning and opening the screen before plugging in their network cable.

As a result, the machine automatically connects to the wireless network first, gets an IP and DHCP registers an A record. Then when the network cable is plugged in, the machine gets another IP and DHCP registers another A record. DHCP seems to update the PTR record.

This is wreaking havoc with the Konica Minolta scan-to-PC FTP utility or connecting to these machines via hostname as I keep querying and getting the IP assigned to the wireless card from DNS and not the one assigned to the cabled Ethernet adapter.


i've configured an user account for DHCP with strong password, set DHCP to run using those credentials, added the DHCP server (which is also the DC) to the DnsUpdateProxy group & secured it and set DHCP to update everything.


How can I go about forcing DHCP to instead update the A record rather than register a second one when the laptops swap from wireless to wired?

Any advice appreciated!
Because you have a DC as a DHCP server, please tell me you've turned on OpenACLOnProxyUpdates?

Anyways, to your problem, if you turn on DHCP Name protection and reduce the wifi lease period to a sufficiently short period like 8 - 10 hours, then the A records and PTR records will be cleaned up by DHCP when the lease expires.
 

ThatOtherDude

Well-Known Member
Joined
Sep 10, 2018
Messages
223
Because you have a DC as a DHCP server, please tell me you've turned on OpenACLOnProxyUpdates?

Anyways, to your problem, if you turn on DHCP Name protection and reduce the wifi lease period to a sufficiently short period like 8 - 10 hours, then the A records and PTR records will be cleaned up by DHCP when the lease expires.

+1

(and restart the DHCP service to ensure it reflects all changes)
 
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