IPAll sets the port for all IP addresses.

Another method to discover TCP ports is by using netstat:

netstat -abno

You should have some rows returned for sqlservr.exe: note down the PID and look it up in the services applet or configuration manager to correlate it to a specific instance of SQL Server.

In your case, it looks like the instance is running on ports 3456 and 1434. The SQLServer Browser service might be running and redirecting you on the correct port (which is strange, since the browser service is not queried for the default port). Try to see if disabling the browser changes the behavior.