Ensure 'Hide Instance' option is set to 'Yes' for Production SQL Server instances

Question

Hi,

We are using SQL Server 2017 in our production environment. We got following requirement from our security team.

*"Ensure 'Hide Instance' option is set to 'Yes' for Production SQL Server instances"**

Is there any impact for database connection if we set 'Hide Instance' option is set to 'Yes'?

Answer 1

Hi @Kazi Ariful Haq ,

> Is there any impact for database connection if we set 'Hide Instance' option is set to 'Yes'?

If you hide a named instance, you will need to provide the port number in the connection string to connect to the hidden instance, even if the browser service is running. We recommend that you use a static port instead of a dynamic port for the named hidden instance.

If you hide a clustered instance or availability group name, cluster service may not be able to connect to SQL Server. This will cause the cluster instance IsAlive check to fail and SQL Server will go offline. To avoid this, create an alias in all the nodes of the clustered instance or all instances that host availability group replicas to reflect the static port that you configured for the instance.

Please refer to MS document Hide an Instance of SQL Server Database Engine to get more information.

Best regards,
Cathy

---

If the response is helpful, please click "Accept Answer" and upvote it.
Hot issues October--Users always get connection timeout problem when using multi subnet AG via listener. Especially after failover to another subnet

Answer 2

This blog post from my fellow MVP Thomas LaRock explains the concept: https://thomaslarock.com/2018/04/how-to-hide-an-instance-of-sql-server/

You will have to determine whether it will have any impact at your site. Note that it does not disable the ability to connect by instance name.