Simulate the Topology

Simulate the Topology Overview

The simulation phase is when you run the simulation of your topology design. The Simulation perspective provides a set of views that support the simulation phase. By comparison, the design and build activities occur in the Design perspective, which provides a set of views that support the design activity. Some views in the Simulation perspective can also be viewed in the Design perspective.

Simulation Perspectives and Views

The main areas of focus within the Simulation perspective are the Simulations view and the Console view. The following figure highlights the Simulations and Console views for a running simulation.

Figure 1. Simulation Perspective Initial Display



From the View menu, you can open additional views in the perspective and arrange the open views by dragging them within the perspective workspace. See the online help and the section Customize Perspectives for more information.

Note
To reset your current perspective to its original configuration when the workbench was first opened, right-click the perspective button and select Reset.

Determining When a Node is Fully Operational

When a simulation starts up, the nodes move through a number of states before their configuration has been applied completely and they are deemed fully operational.

In previous Cisco Modeling Labs releases, a node was marked as [ACTIVE] as soon as the virtual machine had started its boot-up cycle. However, in some cases, it can take any number of minutes before the node is fully operational. Users who have used the Live Visualization functionality will have seen that it is able to detect when a node is responsive to commands. This functionality has been adapted and expanded and a new state is reported in the Cisco Modeling Labs client and in the User Workspace Management interface. This new state [ACTIVE - REACHABLE] is returned when a node has reached the point where its configuration has been fully applied and the node is reachable on its management interface.
Figure 2. [ACTIVE - REACHABLE] State



In this example, the log messages indicate when the nodes have transitioned from startup to the point where the configuration has been applied and the node is now reachable. The state is also reflected in the state marker shown in the Simulations view.

If the management interface is not configured or is in the shutdown state, the node will be shown as [ACTIVE - UNREACHABLE].

Cisco Modeling Labs Active Canvas

The Cisco Modeling Labs client provides users with an active canvas. When a simulation is started and the user switches to the Simulation perspective, a new window opens displaying the network diagram. As the virtual machines start up, the network diagram updates showing the current state of the simulation. Nodes change color depending on their current operational state.

For example, the following figure shows nodes in green which indicates the Active state. Nodes in blue indicate the Build state. Grey nodes indicate the Absent state where a node is yet to be started or has been stopped.

Figure 3. Node States in a Simulation



Once a node is in the active state, you can right-click on the node to perform operations such as opening an SSH or Telnet connection, extract the configuration of the specific node and stop/start the node.

Figure 4. Node Operations



Right-clicking on the background, without selecting a node, enables you to perform simulation-wide operations such as configuration extraction, launch the live visualization view, stop the simulation as well as resetting all link latency, jitter and packet-loss parameters that may be in operation.

Figure 5. Simulations Operations



If the Simulations view is closed, it can be reopened by selecting the simulation from the simulations panel, right-clicking and selecting the View Simulation option.

Figure 6. View Simulation Option



Link latency, jitter and packet-loss parameters can be set by selecting a link, right-clicking and using the Modify Link Parameters option.

Figure 7. Link Parameters



Packet capture operations can be performed by selecting a link, selecting the interface (at one end of the link) and right-clicking to reveal the packet-capture control menu, as shown.

Figure 8. Packet Capture Operations



Once a packet capture has been configured, an icon will indicate that a packet-capture is present on the interface, with the Packet capture view listing the .pcap file that is available for analysis.

Additional diagram labels are now available including interface name, serial port number assignment and so on. These can be accessed from the Show Topology Labels icon on the Cisco Modeling Labs toolbar.

Figure 9. Show Topology Label Options



Launch a Simulation

To launch a simulation, complete the following steps.

Before You Begin

  • Complete the topology design.

  • Complete the task of building the nodes and interfaces.

  • (Optional) Generate the configuration using AutoNetkit.

    Caution
    When you manually make changes to a node configuration and bypass AutoNetkit autogeneration, those changes do not appear in the topology view of the Design perspective or Simulation perspective. For example, if you use the hostname command to change the host name from iosv-1 to Router-1 in the configuration, the node name in the topology view and in other related views remains as iosv-1.

  • Open the desired topology.


    Note
    The topology should be open and visible in the Topology Editor. If you have multiple topologies open in the Topology Editor, simulation will launch for the currently active view.
    Step 1   From the toolbar, click the Launch Simulation button. The simulation launches and provides a unique identifier, which means that multiple instances of the topology can be launched and each will have a unique name.
    Step 2   In the Launching Simulation dialog box, select any of the following actions:

    1. Check the Always run in the background check box. All future node start requests, stop requests, and simulation launch requests run in the background and do not display dialog boxes.
      Note    To control the background setting, choose File > Preferences > General.
    2. Click Run in Background. The dialog box closes when the node simulation starts.
    3. Click Cancel to return to the Design view.
    4. Take no action, and the node simulation launches momentarily.
      Tip    When you click Run in Background, the status bar displays a progress icon. Click the icon to display a compact view of the activity progress. If the background activity encounters an error, the icon shows a red X. Click the error icon to display the error dialog.
    Step 3   In the Simulation launched dialog box, click OK.

    Step 4   When prompted to switch to the Simulation perspective, click Yes.

    Note    We recommend that you switch to the Simulation perspective to view the running simulation and to connect to node consoles.

    The Cisco Modeling Labs client tracks the state of the simulations. All launched simulations appear in the Simulations view. Status messages are displayed in the Console view. After the Cisco Modeling Labs server has started the simulation launch, a confirmation dialog box appears with an identifier assigned to the simulation by the Cisco Modeling Labs server.

    Jumphost Virtual Machine (VM)

    The jumphost VM is the default method for accessing the management network of a running simulation. The jumphost node runs in a separate simulation named ~jumphost and has two interfaces, eth0 in the project/user management network and eth1 in the FLAT network.

    The purpose of the jumphost is to provide an access point into a simulated network that remains fixed, in that there is a single external IP address or port that the user can access. A user can access the jumphost and then access all the nodes inside the simulation.

    Cisco Modeling Labs provides two implementations of jumphost:

    • A VM: Based on the server VM image type.

    • A Linux container: A lighter weight form of a jumphost. See Linux Container (LXC) for more information.

    The VM implementation is costly in terms of the memory and CPU used when a jumphost is instantiated. However, since it is a full-blown server VM, there is value to it, in that you can install and run any application on it.

    To select a jumphost VM, in the Cisco Modeling Labs client, choose Properties > Topology > Management Network > Private project network or Shared flat network.
    Figure 10. Setting the Jumphost Option



    The jumphost VM is per user; a user can create multiple simulations, but only one corresponding jumphost is created. Therefore, depending on the type of simulation you are running, you can choose between the two implementations.

    Linux Container (LXC)

    An LXC provides a means of accessing a topology rather than having to create a full Linux server VM. All nodes in the network are connected to a hidden OOB management network that uses the first interface on each of the nodes.

    In the Cisco Modeling Labs client, it is enabled by selecting the management network type Private simulation network for your topology. The LXC is automatically connected into this hidden OOB management network to which all VMs in your simulation are connected. This enables you to connect into each VM via its management Ethernet port, removing the need to use the console port connection method.
    Figure 11. Setting the LXC Option



    The LXC is operational when your simulation is active and terminates when your simulation stops. LXC uses a significantly smaller memory footprint than the Linux server VM. The LXC automatically gets an IP address on the FLAT network.
    Figure 12. LXC on the FLAT Network



    LXC facilitates SSH access to the VMs; it provides direct SSH access to each VM running inside the simulation. Telnet is not supported. As shown below, LXC is accessed by right-clicking the ~mgmt_lxc [ACTIVE] node and selecting SSH from the list.
    Figure 13. Accessing LXC



    The LXC is automatically spun up and provides a jumphost point for access into the network. Connecting to the LXC means you can see the interfaces to the outside world and to the OOB network inside your simulation.

    A connection is opened from the Cisco Modeling Labs client to a port on the Cisco Modeling Labs server and is forwarded to the LXC. The LXC, in turn, opens a connection to the Management Interface (Gi0/0) of the VM inside the simulation to the node instance.

    Static Port Assignment to the LXC

    When the management network property Private simulation network is set, Cisco Modeling Labs assigns a random port for SSH port access to the LXC. However, you can statically define this by setting an extension on your topology.

    To set an extension for your topology, complete the following steps.

      Step 1   Click on the canvas to open the Topology tab in the Properties view.
      Step 2   Click the Extensions tab.

      Step 3   Click the Add new extension icon. The Edit Extension dialog box appears.
      Step 4   Enter the following values:
      • Key: lxc.host.tcp_port
      • Value: 30799
      • Type: String (from the drop-down list)
      Figure 14. Add a New Extension



      Step 5   Click OK to add the new extension. When the LXC starts, it will be bound to the TCP port specified in the new extension.

      LXC iPerf Container

      The LXC iPerf container provides a stripped down lightweight Linux container which has been loaded with the iPerf application available from Downloads - iPerf.

      iPerf is a tool for the active measurement of the maximum achievable bandwidth on IP networks. It supports tuning of various parameters related to timing, buffers and protocols (TCP, UDP, SCTP with IPv4 and IPv6). For each test it reports the bandwidth, loss, and other parameters.

      Figure 15. LXC iPerf Container



      LXC Ostinato Container

      An LXC container is available that contains the Ostinato packet traffic generator application. This application provides data-plane traffic generation capabilities. The Ostinato drone (generator) is used in combination with the Ostinato GUI. The GUI can be obtained from Downloads – Ostinato.

      When deployed, the LXC Ostinato container can be accessed using the SSH connection method.

      Note
      Telnet does not work.
      The Ostinato drone application executes automatically when the LXC becomes active.

      Note
      The Ostinato drone application should not be installed on the host system as the version in the repositories cannot be executed in the LXC.
      Figure 16. LXC Ostinato Container



      Launch a Phased Simulation

      On occasions, you may need to start your simulation in phases rather than having all nodes launched at the same time. This functionality is facilitated by the Exclude node from simulation launch check box, which allows you to pick and choose which nodes to start.

      To launch a phased simulation, complete the following steps.

        Step 1   With the applicable topology open, click on the canvas and move the selection area over the nodes to be excluded from the running simulation. (Alternatively, you can double-click a specific node, hold down the Shift key, and select the remaining nodes.) The Properties > Node view opens.
        Step 2   In the Properties > Node view, check the Exclude node from simulation launch check box.
        Figure 17. Nodes Excluded from Simulation Start



        Step 3   Save your topology using Ctrl-S.
        Note   

        You can set this property for each individual node, if you prefer. Select the node on the canvas, and select the Exclude node from simulation launch check box in the Properties > Node view.

        Step 4   From the toolbar, click the Build Initial Configurations button to build the node configurations.
        Step 5   From the toolbar, click the Launch Simulation button. The simulation launches.
        When the nodes are running on the Cisco Modeling Labs server, they are displayed in the Simulations view with the status as [ACTIVE].
        Note    In the Console view, you can see the message Node '<node name>' is excluded from automatic start for the excluded nodes, and in the Simulations view, you can see that the excluded nodes have the state [ABSENT].
        Figure 18. Phased Simulation Launched



        Launch Simulation Options

        In circumstances where you need to run a simulation for a specified time frame or you want to specify your own name for a simulation, complete the following steps:

          Step 1   From the menu bar, choose the Simulation button.
          Step 2   From the list, click Launch Simulation with Options.
          Figure 19. Launch Simulation with Options



          The Launch Simulation dialog box is displayed.
          Figure 20. Launch Simulation



          Step 3   If you want to specify your own name or label for the simulation, check the User Specified radio button. Otherwise, leave the default System generated ( based on a file) radio button checked.
          Note    Alternatively, you can specify a simulation name via the User Workspace Management interface; select My Simulations > Launch New Simulation and enter the name in the Simulation Name field.
          Step 4   Set a time duration for the simulation by entering details for Days, Hours, and Minutes by using either the up and down arrows or entering the values directly. Click OK to apply your time limit to the simulation. The simulation launches.
          Note    An expiration warning is displayed ten minutes (or less) before your simulation is due to expire.
          Figure 21. Simulation Expiration Warning



          We recommend that you extract configurations for your simulation before it expires.
          Note    You can reset the time limit for a running simulation in the User Workspace Management interface. See Reset the Time Limit on a Running Simulation for more information.

          Reset the Time Limit on a Running Simulation

          You can extend or reduce the time limit set for a running simulation in the User Workspace Management interface. To do this, complete the following steps.

            Step 1   Log in to the User Workspace Management interface. On the Overview page, information on running simulations is displayed. Move to the applicable simulation under the Session heading. If your simulation is due to expire in ten minutes or less, the simulation name is displayed in red.
            Step 2   Under the Options column, click the down arrow and click Set expiration.
            Figure 22. Soon to Expire Simulation



            Step 3   The Set expiration for session page is displayed. In the date and time field, enter either a new expiration date and time, a date only, or a time only for the simulation.
            Figure 23. Set Expiration for Session Page



            Step 4   Click Set expiration to save the changes. The time limit for the simulation is updated.

            Control Interface States

            In a running simulation, you are able to change the state of the network interface by bringing it up or down.

            Note
            This changes the state of the underlying communication infrastructure, not the interface state of the virtual machine.

            To control the state of an interface, complete the following steps.

              Step 1   Log in to the User Workspace Management interface.
              Note    You must log in as a user other than the uwmadmin user, for example, guest.
              Step 2   On the Overview page, under Sessions, choose the applicable running session. A list of active virtual machines and interfaces is displayed.
              Step 3   Scroll down to the Interfaces section and choose the applicable virtual machine.
              Step 4   From the applicable Options drop-down list, click Update admin state.
              Figure 24. Interface State Control Option



              Depending on the current state of the interface, either a Bring Down or Bring Up page is displayed. In this case, the Bring Down page is displayed.
              Figure 25. Bring Down the Applicable Interface



              Step 5   Click Bring down to bring down the network interface. A message is displayed indicating that the interface has been brought down.
              Figure 26. Interface Successfully Brought Down



              Step 6   To bring up the interface at a later stage, click Update admin state again. The Bring up page displayed.
              Figure 27. Bring Up the Applicable Interface



              Step 7   Click Bring up to bring up the network interface. A message is displayed indicating that the interface has been brought up.
              Figure 28. Interface Successfully Brought Up



              Connect to a Simulation Node Console

              Cisco Modeling Labs provides the capability for you to connect to your nodes via SSH and Telnet. You can start an SSH session, which connects into the node via the LXC, as described in Linux Container (LXC).

              This access method makes use of SSH to the LXC and then Telnet from the LXC to the nodes running inside the simulation. This does not use the console port of the nodes and is more reliable and faster to use.

              Connect to a Simulation Node Console via SSH

              To connect to a simulation node console, complete the following steps.

              Before You Begin

              • Launch a simulation.

              • Ensure that the Simulation perspective is active.

              • Ensure that the Simulations view and Console view are displayed.

                Step 1   To connect to a console for a specific node, right-click the node in the Simulations view and choose SSH > to its Management (via LXC) port.

                Figure 29. Connecting to a Node Console via SSH



                A new Terminal view opens.

                Figure 30. Terminal View



                Step 2   To disconnect a terminal from the simulation, click Disconnect in the Terminal view toolbar or click the Close icon in the Terminal view.
                Note    When you disconnect or close a Terminal view, all text in the view is discarded.
                Tip    When you disconnect a terminal but do not close the Terminal window, you can press Enter to reconnect the terminal.

                Connect to Multiple Simulation Node Consoles

                To connect to all consoles for all nodes in a running simulation, complete the following steps.

                  Step 1   Right-click the simulation in the Simulations view and choose Telnet > to all <number> available Console ports.

                  Figure 31. Connect to Multiple Node Consoles



                  A new Terminal view opens for all console ports.

                  Figure 32. Terminal Views



                  Step 2   To disconnect a terminal from the simulation, click Disconnect in the Terminal view toolbar or click the Close icon in the Terminal view.
                  Note    When you disconnect or close a Terminal view, all text in the view is discarded.
                  Tip    When you disconnect a terminal but do not close the Terminal window, you can press Enter to reconnect the terminal.

                  Terminal Multiplexer Functionality

                  A terminal multiplexer is available for use with the Cisco Modeling Labs client. It permits a number of terminals to be accessed and controlled from a single terminal. Terminals can be detached to run in the background and then reattached later.

                  The terminal multiplexer is available from Window > Show View > Other > General > Terminal Multiplexer.

                  When the terminal multiplexer starts up, a status line at the bottom of the terminal displays information on the current session and is used to enter interactive commands. It lists all of the active console sessions. You can select console sessions individually or all together from the View Menu drop-down list. Keyboard commands entered in the command-line text box are broadcast to the selected sessions.
                  Figure 33. Terminal Multiplexer



                  The terminal multiplexer also provides a command-line history, which you can access using Ctrl-Space.
                  Figure 34. Accessing the Command-Line History



                  Start a Single Node

                  To start a single node, complete the following steps.

                    Step 1   Right-click a stopped node. When a node is stopped, its status is shown as [ABSENT].
                    Step 2   Click Start this node.
                    Figure 35. Start a Single Node



                    The Requesting start dialog box appears.
                    Figure 36. Requesting Start Dialog Box



                    Step 3   Choose one or more of the following actions:
                    1. Check the Always run in the background check box. All future node start requests, stop requests, and simulation launch requests run in the background and do not display dialog boxes.
                      Note    To control the background setting, choose File > Preferences > General.
                    2. Click Run in Background.

                      The dialog box closes while the node simulation stops.

                    3. Click Cancel to return to the Simulations view.
                    4. Take no action and the node simulation restarts momentarily.
                    Tip    When you click Run in Background, the status bar displays a progress icon. Click the icon to display a compact view of the progress. If an error is encountered, the icon displays a red X. Click the error icon to display the error dialog box.

                    Start a Node in a Running Simulation

                    In cases where a phased simulation is running, you can later start those nodes not started with the initial simulation. To start a node in a running simulation, complete the following steps.

                      Step 1   In the Simulations view, right-click the node.
                      Note    A node not yet started has the status [ABSENT].
                      Step 2   Click Start this node.
                      Figure 37. Start This Node Option



                      The Requesting start dialog box appears.

                      Figure 38. Requesting Start Dialog Box



                      Note    The status of the selected node is changed from [ABSENT] to [ACTIVE], indicating that the node is up and running.

                      Start Multiple Nodes in a Running Simulation

                      In cases where a phased simulation is running, you can later start those nodes not started with the initial simulation. To start multiple nodes, complete the following steps.

                        Step 1   In the Simulations view, click the first node in the list to be started.
                        Step 2   Hold down the Shift key and select the remaining nodes.
                        Step 3   Right-click the selected nodes.
                        Step 4   Click Start nodes.
                        Figure 39. Start Nodes Option



                        The Requesting start dialog box appears.

                        Figure 40. Requesting Start Dialog Box



                        Note   

                        The status of the selected nodes changes from [ABSENT] to [ACTIVE], indicating that the nodes are up and running.

                        Figure 41. Multiple Nodes Started



                        Stop a Simulation

                        There are several ways to stop a simulation. In addition, you can stop multiple simulations at the same time. These are discussed in the following sections.

                        Stop a Simulation from the Toolbar

                        To stop a simulation from the toolbar, complete the following steps.

                          Step 1   In the toolbar, click the Stop Simulations button. A Stop Simulation(s) dialog box appears.
                          Figure 42. Stop Simulation(s) Dialog Box



                          Step 2   In the Simulation column, click once to highlight the simulation to stop.
                          Step 3   (Optional) To save the configurations, click the adjacent setting in the Extract Configurations? column until the prompt changes to Yes.
                          Note    Configurations for server nodes are not extracted.
                          Step 4   (Optional) To close the internal terminals associated with the simulation, click the adjacent setting in the Close Terminals? column until the prompt changes to Yes.
                          Note    External terminal connections are not stopped as part of this operation and must be closed manually.
                          Step 5   To stop the simulation, click the adjacent setting in the Stop Simulation? column until the prompt changes to Yes.
                          Step 6   Click OK to stop the simulation, or click Cancel to leave the simulation running.

                          On OS X, you update the values for Extract Configurations?, Stop Simulation?, and Close Terminals? in the columns directly. You do not need to select the name of the simulation.

                          Stop a Simulation from the Simulations View

                          To stop a simulation, complete the following steps.

                            Step 1   In the Simulations view, right-click the simulation name and select Stop Simulation.
                            Figure 43. Stop a Simulation



                            The Stop Simulation Confirmation dialog box appears.

                            Figure 44. Stop Simulation Confirmation Dialog Box



                            • (Optional) Check the Extract Configurations before Stopping the Simulation check box to save the current configurations.

                            • (Optional) Check the Close Associated Terminal Views check box to close all the open internal terminals associated with the specific simulation. External terminals are not closed.

                            Step 2   Click OK to stop the simulation. Once selected, all nodes in the simulation start shutting down. It may take a few minutes for the simulation to shut down completely and to disappear from the Simulations view.
                            Note    For instances where a user account expires, all running simulations for that user continue to run. Since the user account can no longer log in to stop them, they will remain active until the next system reboot or until the system administrator explicitly stops them.

                            Stop Multiple Simulations from the Simulations View

                            To stop multiple simulations, complete the following steps.

                              Step 1   In the Simulations view, click the first simulation in the list to stop.
                              Step 2   Hold down the Shift key and select the remaining simulations.
                              Step 3   Right-click the selected simulations and select Stop Simulations.
                              Figure 45. Stop Multiple Simulations



                              The Stop Simulations Confirmation dialog box appears.

                              Figure 46. Stop Simulations Confirmation Dialog Box



                              • (Optional) Check the Extract Configurations before Stopping the Simulation check box to save the current configurations.

                              • (Optional) Check the Close Associated Terminal Views check box to close all the open internal terminals associated with the specific simulation. External terminals are not closed.

                              Step 4   Click OK to stop the simulations. Once selected, all nodes in the simulations start shutting down. It may take a few minutes for the simulations to shut down completely and to disappear from the Simulations view.
                              Note    For instances where a user account expires, all running simulations for that user continue to run. Since the user account can no longer log in to stop them, they will remain active until the next system reboot or until the system administrator explicitly stops them.

                              Stop a Single Node

                              To stop a single node in a simulation, complete the following steps.

                                Step 1   In the Simulations view, right-click the node to stop and select Stop this Node.

                                Figure 47. Stop a Single Node



                                The Are you sure? dialog box appears.

                                Step 2   Click OK to stop the node. Alternatively, click Cancel to abandon the operation and return to the simulation.
                                Note    When you click OK, the node stops without saving any changes to the configuration.
                                When a node is stopped, its status changes to [ABSENT].

                                Stop Multiple Nodes

                                To stop multiple nodes in a running simulation, complete the following steps.

                                  Step 1   In the Simulations view, click the first node in the list to stop.
                                  Step 2   Hold down the Shift key and select the remaining nodes.
                                  Step 3   Right-click the selected nodes.
                                  Step 4   Click Stop Nodes.

                                  Figure 48. Stop Multiple Nodes



                                  The Are you sure? dialog box appears.

                                  Step 5   Click OK to stop the nodes. Alternatively, click Cancel to abandon the operation and return to the simulation.
                                  Note    When you click OK, the nodes stop without saving any changes to the configuration.
                                  When the nodes are stopped, their status changes to [ABSENT].
                                  Figure 49. Multiple Nodes Stopped



                                  Modify a Node Configuration in the Simulation

                                  You can modify node configurations in a running simulation. To do this, the type of connection available, either SSH or Telnet depends on the option set for the topology property Management Network.

                                  • When Management Network is set to Private simulation network, SSH and Telnet are available.

                                  • When Management Network is set to Shared flat network, Private project network, or not specified, only Telnet is available.

                                  Modify a Node Configuration in the Simulation via SSH

                                  To modify a node configuration in a running simulation via SSH, complete the following steps.

                                    Step 1   Right-click the node in the Simulations view and choose SSH > to its Management (via LXC) port.

                                    Figure 50. Connecting to a Node Console



                                    A new Terminal view opens.

                                    Figure 51. Terminal View



                                    Step 2   If no banner or router prompt is visible, press Enter. You are now working with the operating system running on the node, for example, Cisco IOSv virtual software.
                                    Step 3   Use the operating system commands to view or modify the node configuration.
                                    Note    Changes you make to the configuration do not appear in the canvas of the Topology Editor.

                                    Modify a Node Configuration in the Simulation via Telnet

                                    To modify a node configuration in a running simulation via Telnet, complete the following steps.

                                      Step 1   Right-click the node in the Simulations view and choose Telnet > to its Console port.

                                      Figure 52. Connecting to a Node Console



                                      A new Terminal view opens.

                                      Figure 53. Terminal View



                                      Step 2   If no banner or router prompt is visible, press Enter. You are now working with the operating system running on the node, for example, Cisco IOSv virtual software.
                                      Step 3   Use the operating system commands to view or modify the node configuration.
                                      Note    Changes you make to the configuration do not appear in the canvas of the Topology Editor.

                                      Modify Multiple Node Configurations in the Simulation

                                      To modify multiple node configurations in a running simulation, complete the following steps.

                                        Step 1   Right-click the topology in the Simulations view and choose Telnet > to all <number> available Console ports.

                                        Figure 54. Connect to Multiple Node Consoles



                                        A new Terminal view opens for each of the consoles.
                                        Figure 55. Terminal Views



                                        Step 2   If no banner or router prompt is visible, press Enter. You are now working with the operating system running on the node, for example, Cisco IOSv virtual software.
                                        Step 3   Use the operating system commands to view or modify the node configuration.
                                        Note    Changes you make to the configuration do not appear in the canvas of the Topology Editor.

                                        Extract and Save Modified Configurations

                                        To extract and save modified configurations, complete the following steps.

                                        Before You Begin

                                        • You have modified a configuration within one or more nodes running within the simulation and want to save the changes.

                                        • Ensure that all routers in the simulation are operational before attempting to extract their configurations.

                                          Step 1   In the Simulations view, right-click the topology name, making sure not to click the node name, and select Extract Configurations.

                                          Figure 56. Simulations View Context Menu



                                          A confirmation dialog box appears.
                                          Step 2   Ensure that all external Telnet connections to the simulation are closed before proceeding.
                                          Note    You must close all external Telnet connections to the simulation before you can proceed.

                                          Figure 57. Extract Configurations Dialog Box



                                          Step 3   Click OK.

                                          The Extracting Configurations dialog box appears indication that the extraction is in process.

                                          When the extraction is complete, a message is displayed.

                                          Figure 58. Extraction Complete Message



                                          Note    The configuration information is extracted and saved in the filename.virl file that corresponds to the topology. For example, the file New_Topology that is running as a New_Topology-dkIFaW simulation has its configuration extracted to the file New_Topology.virl.
                                          Step 4   Click OK.

                                          Partial Configuration Extraction

                                          During a configuration extraction, if the process encounters issues or fails for a particular node, the problem node is identified and reported.

                                          The extraction process then continues for all other nodes in the simulation and returns collected configurations to you.

                                          Linux Server Snapshot Support

                                          When a Linux server is present in a running simulation, you can use the User Workspace Management interface to take a snapshot of the disk content of the server. This newly created user-specific disk image can be used in other simulated sessions.

                                          To take a snapshot of the server's disk contents, complete the following steps.
                                            Step 1   Log in to the User Workspace Management interface.
                                            Note    You must log in as a user other than the uwmadmin user, for example, guest.
                                            Step 2   On the Overview page, under Sessions, select the applicable running simulation.
                                            Figure 59. Running Simulation Listed



                                            A list of active VMs is displayed.
                                            Figure 60. Active VMs



                                            Step 3   Select the applicable Linux server, and from the Options drop-down menu, click Create snapshot.

                                            Figure 61. Create Snapshot Option



                                            Project details for the newly created snapshot are displayed.
                                            Figure 62. Newly Created Disk Image



                                            Reuse the Image Snapshot

                                            To reuse the image snapshot, complete the following steps.

                                              Step 1   Create a new topology or open an existing topology.
                                              Step 2   On the canvas, add a node to the topology.
                                              Step 3   Select the node on the canvas. The sample topology opens in the Topology Editor canvas.
                                              Step 4   In the Properties > Node view, click Browse beside the VM Image field. The Select VM Image dialog box appears.
                                              Step 5   Select the applicable image snapshot and click OK.
                                              Figure 63. Select the Image Snapshot to Use



                                              Details for the image snapshot are visible in the VM Image field under Properties > Node view.
                                              Figure 64. Image Snapshot Selected



                                              Latency, Jitter and Packet Loss Control Options

                                              The availability of link-level parameters allows users to investigate and understand the impact on services of transmission characteristics encountered in the physical world. With a running simulation, you are able to select links between the nodes in the simulation and set latency, jitter and packet-loss values on those links. This enables you to create links that have properties seen in the physical world such as transatlantic or transcontinental latencies or packet-loss.

                                              The link parameters can be applied on any link, except for those connected to a FLAT or SNAT external connector. The values set by the user are applied bi-directionally, meaning that setting a latency value of 100ms results in 100ms from node A to node B and 100ms from node B to node A for the return path. That is 200ms in total. The same is true for packet-loss. Ten packets sent from node A on a link with 10% packet-loss results in 9 packets being received on node B. The packet loss will also be applied on the return path meaning that another packet may be lost between node B and node A.

                                              You can set these link-level parameters in one of three ways:
                                              • In the Cisco Modeling Labs Client client.
                                                Figure 65. Setting Link Parameters in the Cisco Modeling Labs Client



                                              • In the User Workspace Management interface.
                                                Figure 66. Setting Link Parameters in the User Workspace Management Interface



                                              • In the Live Visualization view of the running simulation.

                                                Figure 67. Setting Link Parameters in the Live Visualization View



                                              Coordinated Packet Capture

                                              When inspecting traffic passing across the network, it can be valuable to be monitor more than one interface at a time and also to start the packet capture at the same time. Coordinated packet capture capabilities is provided in the User Workspace Management interface. When a simulation is up and running, you can select one or more interfaces and mark them for traffic capture. You are then able to specify the traffic capture parameters including the packets to match (using PCAP filter syntax), the time to run the capture, or the number of packets to capture. You can either start the capture on the marked interfaces immediately, or do so at a later point in time.

                                              Once complete, you can either download the per-interface .PCAP files or output to a .ZIP file containing the .PCAP files for each interface.

                                              Using the Coordinated Packet Capture Feature

                                              To use the coordinated packet capture feature, complete the following steps.

                                                Step 1   From the Cisco Modeling Labs client toolbar, click Launch a Simulation to start the simulation.
                                                Step 2   Log in to the User Workspace Management interface and click the My simulations option as shown.
                                                Step 3   Under the Interfaces panel, select the applicable interfaces.
                                                Figure 68. Select the Interfaces



                                                Step 4   Once all interfaces are selected, click the Traffic Capture option. The Create Capture page is displayed.
                                                Figure 69. Create Capture Page



                                                The selected interfaces are displayed in the Interfaces panel.
                                                Note    You can change your interface selection at this time. You can add new interfaces or remove the selected interfaces.
                                                Step 5   Under General Settings, provide a name for your capture grouping.




                                                Step 6   Specify any packet capture limits for packets (count), size (MB), and time (seconds) in the Capture Limits panel.
                                                Step 7   Click Create. A confirmation message is displayed indicating that the capture group was successfully created.




                                                Step 8   Under the Traffic Captures panel, all entries are listed, with the running status False, as shown.
                                                Figure 70. Traffic Capture List



                                                Step 9   Click the Start icon to start the capture.
                                                Figure 71. Start the Traffic Capture



                                                Note    All of the packet captures are run simultaneously and the running statuses change to True. If you continue to watch the Traffic Capture panel, you will see as the packet captures complete, the running statuses change to False again.
                                                Figure 72. Running the Traffic Capture



                                                Step 10   You have the option to download each .PCAP file individually or all of them together in a .ZIP file.
                                                Figure 73. Download Individual .PCAP Files



                                                Figure 74. Download a .ZIP File



                                                Click the applicable option.
                                                Step 11   For the ZIP file option, you can see the list of packet capture files, as shown.
                                                Figure 75. The List of Downloaded Packet Capture Files



                                                You can view the packet capture details as required.

                                                Real-time Traffic Visualization

                                                When a simulation is running, you can log into the User Workspace Management interface as the user under which the simulation was launched. If you choose My Simulations and select the applicable simulation, the Show Traffic option is available on the right-hand side, as shown.
                                                Figure 76. Show Traffic Option



                                                Choosing this option displays a table of all of the interfaces in the simulation, with traffic counters showing the amount of traffic sent and received on each interface.
                                                Figure 77. List of Interfaces



                                                You can select a subset of the interfaces that you want to display as a graph using the Add Graph. This operation displays the data from the last 1, 5 or 10 minutes or from a Live graph.
                                                Figure 78. Graph and Live Graph Options




                                                Note
                                                In cases where the RX/TX packet and byte counters report loading and do not populate with values for a running simulation, clearing your browser cache will resolve this issue.