For more information regarding the security incident at F5, the actions we are taking to address it, and our ongoing efforts to protect our customers, click here.

Forum Discussion

James_Anderson's avatar
James_Anderson
Icon for Nimbostratus rankNimbostratus
Nov 13, 2025

Cannot automatically add the LTM virtual server to DNS

Hi Team,   I'm having an issue while configuring GTM. DNS is able to connect to the BIG-IP LTM, but it cannot automatically add the LTM virtual servers to DNS. I checked the iqdump, and it does con...
GTM DNS
James_Anderson's avatar
James_Anderson
Icon for Nimbostratus rankNimbostratus
Nov 13, 2025

Hi,

 

Checking the iqdump shows that TCP port 4353 is allowed between the BIG-IP DNS system and the target BIG-IP systems. There is no router or firewall between the DNS and the LTM, so there is no network address translation involved. I have already enabled these features, but I still don't see any VS entries in the GUI.

Configure global auto-discoveryConfigure virtual server auto-discoveryConfigure link auto-discovery

 

F5_Design_Engineer's avatar
F5_Design_Engineer
Icon for MVP rankMVP
Nov 19, 2025

James_Anderson​ 

Have you created a LTM entry in GTM here

DNS → GSLB → Servers

 

Check the virtual server

 

tmsh show gtm server <server-name> virtual-servers