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Nikoolayy1's avatar
Aug 26, 2025

DNS/GTM health monitor big3d timeout because of alias config

Hello Everyone,

 

I was testing some experimental config for DNS/GTM where the health monitor does not monitor the pool members but a specific IP address configured in the "alias" and it does not work as the error says bigd timeouts to report the state.

 

For LTM http/https health monitors the "alias" option works but not for gtm/dns. I think I discovered a bug as this is rare use case to not monitor the pool members themselves.

 

I have changed the ip to 1.1.1.1 just for the picture screenshot 😄

 

Also in the logs after gtm and big3d is enabled I see the logs below and too bad that F5 DNS does not have monitor debug like LTM to just enable a debug for a monitor and not the entire box.

 

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Will not probe x.x.x.x:80 ( in DC /Common/niki-dc because will be done by other GTM (<unknown>:<unknown>)

Unable to identify which gtm server represents the local device

 

 

 

 

1 Reply

  • ok resolved the issue by looking at the logs as did not add the F5 gtm/dns itself as a server in the GSLB config as to be selected for monitoring and now the "alias" ip address is monitored even without adding it as a server object. Someone has to read the logs 🐸