We use a tool named Redseal (https://www.redseal.net/) to collect and report on network devices and boundaries. Redseal supports an Azure "plug-in" that calls the Azure portal and retrieves security-relevant VNET and NSG information. The plug-in's configuration requirements are attached (see page 2), along with our proposed use of them (page 3).

We already use Redseal to gather information for vnets spread across several subscriptions in our Azure tenant, including one managed in our address space by a third party. We'd like to extend this ability into our area of the Atlas tenant.

The value to us is that we will be able to better understand our overall network security posture, given the need to peer vnets in our tenant with the Atlas tenant.