Interactive Scenarios Window
Interactive Simulation allows you to specify the nodes, trunks, or facilities that you want to fail for the simulation run. Subsequent failures can also be performed by continuing the simulation using a different set of failed elements.
In the Juniper NorthStar Planner window, select Simulation > Interactive Scenarios. The Interactive Scenarios window Node tab is displayed as shown in Figure 1.
To fail a node, select it. The node appears dimmed on the topology map to indicate its failure.

To fail selected links in the network, select the Link tab. The Interactive Scenarios window Link tab is displayed as shown in Figure 2.
A list of all links is displayed. To fail a link, select it. The link appears dimmed on the topology map and marked with a red (F) symbol to indicate its failure. To bring the link back up, select the failed link again. To bring all links back up, select Reset Simulation.

To fail selected SRLGs in the network, select the SRLG tab. The process is similar to link failure simulation.
The Interface tab functionality is not currently supported. This tab is reserved for future functionality.
The following list explains the Run, Step, and Stop buttons:
To run a simulation with the given failures, click Run. The scenario runs, and the stop button is displayed.
To step through a simulation, click Step. A step consists of the rerouting of a single tunnel. For each step, a Paths window appears indicating the rerouted path (if any) and the disconnected path. This feature is applicable only when a running simulation has been stopped.
To stop a running simulation, click Stop (only visible when a simulation is in progress).
To see how the failure impacts link utilization or tunnel routing, run the simulation and then select View Changes > View Link Changes or View Changes > View Tunnel Changes.
The following changes can be viewed after performing the interactive simulation:
Click Reset Simulation to reset the simulation to the initial network state. All trunks and nodes are set to active, and all tunnels are routed according to the state at which the simulation mode was entered.