Mar 27, 2026 - For details about updated CVE-2025-53521 (BIG-IP APM vulnerability), refer to K000156741.

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Mostafa-Abdou's avatar
Mostafa-Abdou
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Feb 23, 2026

F5 DNS Express

Hi Brothers,

        I have an issue with F5 DNS Express , I configured it as a secondary DNS server and AD as Primary DNS Server , the first issue that when F5 received Notification from AD it not send Zone transfer Request to AD , the second issue that when i configure the F5 listener as preferred DNS on user Machine this Machine can not join Domain even all required Records are available on F5. 

If you have any recommendation please advise.

 

Br, 

3 Replies

  • Hello Mostafa-Abdou​ 

    I noticed that Paulius has directed you to a post that could assist in solving your question and wanted to encourage you to update your post if it has assisted or if you are needing additional assistance. 

    -Melissa 

  • Hello.

     

    1. Could you first check your DNS Express settings?

     

    DNS ›› Delivery : Nameservers : Nameserver List

    The AD server IP address should be registered as the nameserver here.

    (TSIG and other settings must be identical to AD.)

     

    Then, in

    DNS ›› Zones : Zones : Zone List

    register the zone you want to delegate to DNS Express.

    At this point, register the nameserver as the AD nameserver you created above.

    (Similarly, decide whether to use TSIG and configure the settings accordingly.)

     

    You said you're not sending a transfer request when you receive an alarm.

    Can you try adding the AD server IP address to Allow NOTIFY From?

     

    2. Are all domains registered in the zone and receiving them in the transfer format?

    Or are they registered in WideIP and are they fixed?

    Why aren't you receiving a response? Timeout? No error? (WideIP settings take precedence over zone settings.)

     

    If we could view actual DNS requests and responses using tcpdump, we could conduct a more detailed analysis.

     

    I hope this helps.