One software license is required per server.

Redgate license SQL Monitor per server to keep things transparent - for you and them.
'Server' in this context refers to a distinct system running a Windows operating system with SQL Server.

For example, if you have five physical servers you want to monitor, each running a Windows operating system with SQL Server, you will need a five-server license of SQL Monitor. Licensing for SQL Monitor depends on the number of servers you wish to monitor. You only need to license each server you wish to monitor, even if you have more than one instance of SQL Server running and even if you have a multi-processor server.

Redgate recommend you install SQL Monitor's Alert Repository on a different server to any you wish to monitor. To keep things simple for you, no additional license needs to be purchased for SQL Monitor's Alert Repository.

Clustered environment
If the servers you are monitoring are clustered, whether it's active/passive or active/active, you will need a license for each node that is running SQL Server.

Virtual environment
If you host the servers you're monitoring in a virtual environment, you will need a single server license for each virtual server that runs SQL Server. For example, if you have five physical servers hosting 10 virtual servers, you will need a 10-server license of SQL Monitor.

Support and upgrades
For the duration of the purchased support period; 1 Year, 2 Years or 3 Years, you will receive:

• Free upgrades: when a new major version of the software is released, you'll get it for free.
• Full support: if you hit any problems, you can speak to a dedicated product support engineer by email, forum, or phone.