Is it possible to install WordPress Multisite on a subdomain with subdirectories?

This is something I have never tried so far. On a webspace I want to have a subdirectory like this:

blognetwork.example.com

Then I want to run Multisite with subdirectories like this:

blognetwork.example.com/blog/ blognetwork.example.com/site1/ blognetwork.example.com/site2/ 

Is this possible or will it lead to unpredictable issues? Someone ever tried this?