Network and application protection
This section introduces the core solutions available in Azure to protect and secure the network and applications running in Azure; this section also covers solutions that, while not part of the exam objectives, have been included with brief coverage as they should be considered required knowledge for a day-to-day Azure role.
NSGs
An NSG is a network security control and should be part of your DoD approach to protecting the network layer from network threats.
An NSG controls access, limits connections to virtual machines (VMs) in an Azure Virtual Network (VNet), and uses a deny-by-default policy; this means that all access is denied unless explicitly allowed. The following diagram shows a simplification of this:
In the preceding diagram, Subnet 1 has no traffic filtering in place, so you would be able to connect to Windows VM1 using Remote Desktop Protocol (RDP) on port 3389
, and so can...