Why can't I do a connection test to a SQL SERVER database?

[havalos]

I am trying to connect to SQL SERVER 2016 database, but not
I can connect, when I try, it shows me the following error:

SQLState - 08S01
com.microsoft.sqlserver.jdbc.SQLServerException: The connection to the host 172.16.100.244, named instance MSSQLSERVER failed. Error: "java.net.SocketTimeoutException: Receive timed out". Verify the server and instance names and check that no firewall is blocking UDP traffic to port 1434. For SQL Server 2005 or later, verify that the SQL Server Browser Service is running on the host.

But I do not understand why? ... if port 1433 is open and I install SQL STUDIO I execute a connection and if it connects.

[Nic Brough -Adaptavist-]

This is what it says it is - there's no useful route between your Confluence Server and your database server.

Your statement that "1433 is open and talks to SQL Studio" is a useful debugging thing, but please re-read the error message again - it's not the same port.

[havalos]

Yes, the message indicates port 1434, what I don't understand is the use of that port since I don't have any application running on that port, according to the installation manual the default port is 1433 for SQLSERVER.

[Nic Brough -Adaptavist-]

It will have taken the 1434 from the connection settings you gave it during installation.  Check the settings you are giving it for the connection.

You may however have left the port blank and it's assumed a default, and there are a couple of things that might kick in here

• There might be an environment setting that is telling it the default is 1434.  I don't actually know how that might be done, or even if it is possible, but I can't rule it out.
• It might also be guessing at 1434 because you've installed Confluence before, and used 1433 for that.  Also a bit of a guess, but if you've installed Confluence before and run with the defaults, a new install will create new users and other settings from the defaults by adding 1 to them on each install

However, the "why" of this is not that important - go back to the connection settings screen and look at the connection settings, especially the port - that needs to be 1433 (assuming that's where the database is listening)