Last Modified: Nov 20, 2025
Affected Product(s):
BIG-IP DNS, GTM
Known Affected Versions:
15.1.3, 15.1.3.1, 15.1.4, 15.1.4.1, 15.1.5, 15.1.5.1, 15.1.6, 15.1.6.1, 15.1.7, 15.1.8, 15.1.8.1, 15.1.8.2, 15.1.9, 15.1.9.1, 15.1.10, 15.1.10.2, 15.1.10.3, 15.1.10.4, 15.1.10.5, 15.1.10.6, 15.1.10.7, 15.1.10.8, 16.0.1.1, 16.0.1.2, 16.1.0, 16.1.1, 16.1.2, 16.1.2.1, 16.1.2.2, 16.1.3, 16.1.3.1, 16.1.3.2, 16.1.3.3, 16.1.3.4, 16.1.3.5, 16.1.4, 16.1.4.1, 16.1.4.2, 16.1.4.3, 16.1.5, 16.1.5.1, 16.1.5.2, 16.1.6, 16.1.6.1, 17.5.1.3
Opened: Oct 14, 2021 Severity: 3-Major
The datacenter configuration object does not validate configuration changes for prober-preference and prober-fallback, and it allows creating an invalid configuration. If BIG-IP DNS is in a bad configuration state, a configuration load can fail with an error similar to this: 01071b63:3: The prober fallback value for server /Common/server1 cannot be the same as the inherited prober preference value. Unexpected Error: Validating configuration process failed. or 01071b62:3: The prober preference value for server /Common/server2 cannot be the same as the inherited prober fallback value. Unexpected Error: Validating configuration process failed. This error occurs because the prober-preference and prober-fallback cannot be set to the same method. When a gtm server object inherits the prober preference or fallback value, they must not be set to the same value.
Two prober-pool configurations for a GSLB server is a prohibited state. Once this state is reached, any action that tries to validate the configuration (like a configuration load) will fail. This can cause the BIG-IP to fail to load configuration or cause a UCS restore to fail.
1. GSLB server has a prober-pool and inherits the datacenter selected for prober preference or prober fallback (it does not matter which prober configuration has which value). 2. GSLB datacenter is modified such that the prober configuration inherited by the constituent GSLB server is changed from a non-pool method to prober-pool. This results in the GSLB server having a prober-pool probe configuration manually configured and another prober-pool probe configuration inherited from the GSLB datacenter.
Review the configured and inherited prober configuration state of all GSLB servers whose parent GSLB datacenter has a prober-pool configured for it's prober preference or prober fallback. If any GSLB servers are affected, change their prober configuration so that only a single prober-pool configuration exists; or, you can change the parent GSLB server to no longer use the prober-pool method. To do that, the following commands will help to identify a gtm server configuration object with invalid configuration. 1. Save the configurations into file. # tmsh save sys config partitions all 2. Verify the BIG-IP DNS configurations. The error will give you the name of the gtm server configuration object with an invalid configuration. # tmsh load sys config partitions all gtm-only verify 3. Fix one by one by repeating step 2 until the verify command succeeds.
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