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DNS / DHCP TTL for non-windows clients RRS feed

  • Question

  • Hi,

    I have A DHCP/DNS configuration ( with dynamic updates ) on a windows 2008R2 server.

    I can manage the TTL settings for manually created records in the properties tab from the dns zone. ( 2 hours now )

    If i am corrcet, these settings do not apply to dynamic updates.

    The default TTL -time for dynamic updates is 20 minutes and the only way to change tis is with a DNS group policy setting?

    In that case ,  i suppose it only affects windows devices?

    If i check the TTL for non-winodws devices, ( also dynamic updates) i see, they all have a TTL from 15 minutes.

    Any idea where i can change this?

    Tx,

    Friday, September 21, 2018 1:24 PM

All replies

  • Hello,

    The default TTL time for dynamic updates is 20 minutes and the only way to change tis is with a DNS group policy setting ?

    You are right :

    In that case, I suppose it only affects Windows devices ?

    You are right

    Best Regards,

    Friday, September 21, 2018 3:04 PM
  • Hi,

    Just want to confirm the current situation.

    Please feel free to let us know if you need further assistance.

    Best regards,

    Michael


    Please remember to mark the replies as an answers if they help.
    If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com

    Tuesday, September 25, 2018 10:00 AM
  • Hi,

    Yes, i hope to receive an answer on this : ( my last question )

    If i check the TTL for non-winodws devices, ( also dynamic updates) i see, they all have a TTL from 15 minutes.

    Any idea where i can change this?

    Regards,

    Tx,

    Tuesday, September 25, 2018 12:05 PM
  • Hello,

    Regarding non windows devices you should check if they have configuration file to do it

    Best Regards,

    Tuesday, September 25, 2018 1:16 PM
  • No, they  a config file todo that, they receive the ttl from the dns server

    Wednesday, September 26, 2018 8:32 PM
  • they don't have a config file , they receive the TTL from the DNS server
    Wednesday, September 26, 2018 8:33 PM
  • Ok can you go in the properties of the zone where your computers register, in the Start Of Authority tab you have a value for Minimum (default) TTL which value do you have ?

    Below an article regarding how DNS works and how records can inherited TTL from the zone configuration :

    https://technet.microsoft.com/pt-pt/library/cc772774(v=ws.10).aspx

    Best Regards,

    Thursday, September 27, 2018 6:42 AM
  • 2 hours, but are these settings not only for manually created records? and not for dynamic created records?
    Thursday, September 27, 2018 5:50 PM
  • What do you mean by that ?

    Because in my first answer you have the parameter for Windows OS and in the last it is for all type of dynamic records

    Best Regards,

    Friday, September 28, 2018 7:52 AM
  • ok, sorry for the possible misunderstanding, indeed the first answer was for te windows devices.

    Concerning your last answer , i had read somewhere that these settings were valid only for records that you add manually.

    If i look to records that i create manually, they have a TTL from 120 minutes, like specified in the SOA-tab, but  my  non-windows devices not ,( dynamically updated ) they receive a TTL from 15 minutes from the DNS server.

     


    Monday, October 1, 2018 8:40 AM
  • Ok maybe you can try what is defined here to adjust the value :

    https://docs.microsoft.com/en-us/windows/desktop/ad/configuration-of-ttl-limits

    Best Regards,

    Monday, October 1, 2018 11:36 AM