One challenge that the Blue Team might face when dealing with networks that are already in production is understanding the topology and critical paths, and how the network is organized. One way to address this issue is to use a networking map tool that can present the current network state. One tool that can help you with that is the Network Performance Monitor Suite from Solarwinds. After installing it, you need to launch the network discovery process from the Network Sonar Wizard, as shown here:

You need to fill in all these fields before you click NEXT, and once you finish, it will start the discovery process. At the end, you can verify your NetPath, which shows the entire path between your host and the internet:

Another option available in this suite is to use the network atlas to create a geolocation map of your resources, as shown here:

When discovering your network, make sure that you document all aspects of it because you will need this documentation later on to properly perform the segmentation.