Nagios Support Forum

I have added a domain to monitor for Domain Expiration.
The service "Domain Expiration" is UP and OK( it shows the expiration date), but the host is shown as Down and the message it shows is : HTTP CRITICAL - Unable to open TCP socket.

What causes this problem and how to solve it?
Thank You.

Hello, @Armela.
Can you show us the command and the service definition for this check? You can find these in Core Configurations Manager.
You may also run the command through the command line with the -v flag to get a more detailed troubleshooting message.