Issue
Can the MPM be connected to the Internet (ie: given a public IP address)?
Environment
All MPM models
Cause
Request from end customer
Resolution
Although current versions come with Digest Authentication, the MPM must NOT be connected directly to the Internet or any other public network.
It should only be made accessible over the Internet by using VPNs, firewalls, and remote software with strong passwords.
This Application Note provides the above information in official terms.