DNS scavenging and computer which make logon after many weeks

Question

I'd like to enable DNS scavenging in Windows 2012 R2 environment.

I have no DHCP server and all Windows clients have their static ip adress but DNS server has dynamic entries infact they are created when computer is joined to MS domain.

It often occurs DNS server contains old entries so It's necessary to clean up It e.g. when computers which are joined to domain for test.

If user goes on holidays and computer is kept powered off for more 2 weeks and computer name entry is been deleted in dns server by scavenging feature, when He comes back to office He is able to logon on Microsoft domain?

I read client communicates to DNS server every 24 hours but if I take computer as sample, which makes logon every day, DNS timestamp doesn't show recent date.

Perhaps before to check these steps I have enable aging of Resource record ?

Answer 1

Hello,

Enabling DNS scavenging in your Windows Server 2012 R2 environment can help you clean up stale DNS records. Here are some important steps and considerations to ensure everything works smoothly:

Steps to Enable DNS Scavenging:

1. Enable Aging and Scavenging:
   • Open the DNS Manager.
   • Right-click the DNS server and select Properties.
   • Go to the Advanced tab.
   • Check the option Enable automatic scavenging of stale records and set the scavenging period (e.g., 7 days).
2. Set Aging for Resource Records:
   • Right-click the relevant DNS zone and select Properties.
   • Go to the General tab.
   • Click on Aging.
   • Enable Scavenge stale resource records.
   • Set the No-Refresh and Refresh intervals. These intervals determine how often records will be refreshed and when they will be eligible for scavenging. For example, 7 days for both.
3. Verify and Apply:
   • Apply the settings and ensure that the changes propagate to the relevant DNS zones and records.

Important Considerations:

1. Static IP Addresses:
   • Since your clients have static IP addresses, ensure that each of them is configured correctly and consistently, with the Register this connection's addresses in DNS option checked in the IP settings of each network adapter.
2. Computer Logon after Scavenging:
   • Regarding your concern about users logging on after being away for more than two weeks, if the DNS record is scavenged, the computer should still be able to log on to the domain. When the computer is powered on and connected to the network, it will attempt to register its DNS record again. However, ensure that the No-refresh and Refresh intervals are configured correctly to avoid premature deletion of records.

For more detailed information, refer to the documents: Troubleshoot DNS scavenging issues - Windows Server | Microsoft Learn

3. Client Side Configuration:
   • Ensure that your clients are configured to dynamically update DNS records.
   • Go to the network adapter settings on the client.
   • Select Internet Protocol Version 4 (TCP/IPv4) and click Properties.
   • Go to Advanced > DNS and make sure Register this connection's addresses in DNS is checked.
4. DNS Record Timestamps:
   • The timestamp of a DNS record is updated when the record is refreshed.
   • Dynamic updates occur when the client boots up, renews its lease, or every 24 hours as per the configured settings.
5. Testing:
   • After applying these settings, it is beneficial to monitor a few clients to ensure that the records are being updated and scavenged as expected.
   • Use tools like ipconfig /registerdns on client machines to force a DNS update if necessary.

By following these steps and considerations, you should be able to implement DNS scavenging in your Windows Server 2012 R2 environment while ensuring that users can still log on to the domain after periods of inactivity.

I hope the information above is helpful.

Best Regards,

Yanhong Liu

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Answer 2

I thank you for your complete and precice explanation which I understood quickly.

Static IP Addresses:

• Since your clients have static IP addresses, ensure that each of them is configured correctly and consistently, with the Register this connection's addresses in DNS option checked in the IP settings of each network adapter.

About Windows Client I'm using this option: Register this connection's addresses in DNS

About Linux/Windows server or other devices like network printers, access point...

I assigned to them a static IP address but some of them but they are registered into DNS as dynamic resource records e.g. MS windows server which joined to domain.I know scavenging mechanism is not applied to static entries of DNS (do you confirm please?) but I can convert dynamic entries to static ones so that they cannot become stale records ? So I can to be sure no dns server entry is deleted.

How can I convert them ? Is there way to collect and process them all together?