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

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Arron_F's avatar
Arron_F
Icon for Nimbostratus rankNimbostratus
Jan 22, 2025

Configuring iQuery for GTM / DNS

Hi,

We're starting to look at implementing GSLB for various of our external services.

All of the documentation says we should add our BIG-IP devices in our other data centers via DNS > GSLB > Servers and add using its external IP address.

We do not connect our F5's directly to the internet, instead the NAT is handled by our Firewalls. What IP should I use or how should i configure the server? 

With just their internal management IPs? (Both datacenters are linked via Layer 2 direct fibre so we can contact without having to go out externally)

With the IPs they have in our pool subnet?

Or do i add and put the external address that the GTM DNS listener will be on and have a translation to the internal GTM DNS listener address? 

 

Any pointers are appreciated. 

Thanks

1 Reply

  • Anoop_Jayadharan's avatar
    Anoop_Jayadharan
    Icon for Cirrus rankCirrus
    Jun 01, 2026

    Hey Arron_F​ 

    In your case, add BIG-IP LTMs into the DNS using their internal Self-IPs, assuming they are reachable through the MPLS/dark fibre

     internally. IQuery would happen through this private link. However, when you define virtual servers within the server objects, the following procedure is recommended. 

    You can add either a virtual server or a pool-level monitor to achieve more precise control. 

    #####################################################################

    Creating BIG-IP LTM virtual server objects for BIG-IP servers that reside behind a firewall, NAT

    The IP address that you define as the virtual server address for a BIG-IP LTM virtual server is the internet-facing firewall NAT address that clients use to access the virtual server services. The translation address of a virtual server is the private network address defined for the virtual server on the BIG-IP LTM system.

    For example, consider a case in which the BIG-IP LTM system's virtual server private network address is 10.0.0.111, and the firewall Internet-facing NAT address is 65.61.115.223.

    When you add the BIG-IP LTM system's virtual server to the BIG-IP DNS system, you enter the IP addresses in the General Properties section, as follows:

    Address 65.61.115.223

    Translation 10.0.0.111