It is easy to enable maintenance mode in single site installations but on multisite network there are multiple websites and various users so single site plugins not always work on multisite networks especially if you want to force network wide maintenance mode so that no-one can login in between maintenance period.
Multisite Maintenance Mode is the new WordPress plugin that disables logins for all your site users except network administrators. The plugin simply direct every user (excluding network admins) to their homepage when they attempt to log in.
The plugin also displays a message in admin bar to direct them on where to find more information.
Installation & Usage:
- Install and network activate Multisite Maintenance Mode plugin
- Visit Network Settings -> Multisite Maintenance Mode
- Turn on Multisite Maintenance Mode