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DNS Record Timestamp Replication RRS feed

  • Question

  • Hello

    There are 3 DNS servers in my environment. For a long time scavenging have been disabled. Now timestamp for servers are for more than 1 year ago and its different on 3 DNS servers. My question is if I enable scavenging now, would it delete the records that has not been updated?

    If yes, when I run ipconfig /registerDNS timestamp will be updated on one of DNS servers. I need to know Timestamp Replication rules between DNS servers. What is the safest way to enable scavenging in this situation? I dont want to remove any live records.

    Thanks in advance



    Monday, January 7, 2019 12:42 PM

Answers

  • Hi,

    There are some misconceptions prompting fears that Scavenging will remove everything in your zone, includind servers. Please understand, the main thing that scavenging works on is the timestamp. If there is no timestamp, such as a manually created, static record, it will not get scavenged. Also, if all servers, including DCs, are automatically updating their own record, then there is no fear of losing their records, because for one, their records (timestamps) are current, therefore scavenging won’t touch them, and two, Windows Servers by default will update their records every 24 hours, with the exception of domain controllers at every 60 minutes. Therefore, even if they were to scavenge these records, assuming the time stamp has ever been reached, the machines will refresh themselves anyway!

    If DNS aging and scavenging is not enabled on an AD-integrated DNS zone, there is no need to replicate DNS resource records’ timestamps. 

    When DNS aging and scavenging is enabled on an AD-integrated DNS zone, the update of a resource record timestamp will start to be replicated to other DC/DNS servers.

    Scavenging Refresh and No Refresh settings must be equal to or less than the lease period. For example, using  the default DHCP lease period of 8 days with a 7day scavenge setting, is perfect.

    Please refer to the link below:

    https://social.technet.microsoft.com/wiki/contents/articles/21724.how-dns-aging-and-scavenging-works.aspx  

    Best regards,

    Travis


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    Tuesday, January 8, 2019 2:06 AM
    Moderator