Connecting to the default instance of SQL Server connects to a named instance I have 2 instances of SQL Server installed on one server: SQL002.

One instance is a default instance, SQL2008 R2, and the SQL service is generally not running except for specific tests.

The other instance is a named instance, SQL 2014 (so SQL002/SQL2014). This is generally running all the time.

Today I just had a developer tell me that when they connect to SQL002 in SQL Server Management Studio it will connect successfully. I replicated this from my machine and also see a successful connection, however when I look at the properties of the connection it is reporting that it connected to the named instance.

What is going on here? Is there a redirect I'm not aware of?
There can be three reasons:


SQL Aliases: either you or that  dev has an alias
Named instance running on port 1433. Connecting to the default instance means just connecting with port 1433 instead of asking the sql browser first (only applies to tcp) 
Explicit port inside the connection string