- Overview
- Product Documentation
- CML 2.8 Release Notes
- CML 2.8 Installation Guide
- CML 2.8 User Guide
- CML 2.8 Admin Guide
- CML Administrator's Guide
- Cisco Modeling Labs System Overview
- System Defaults
- Creating a New Node Definition
- Node Definition SMBIOS Parameters Specification
- Custom VM Images
- Clustering
- CML Admin Tools
- System Settings
- Networking
- Resources
CML Reconfiguration¶
At the first boot of CML server, you are presented with an interactive setup dialogue allowing users to configure various parameters in CML. After the initial installation, there could be certain scenarios where CML server needs to be reconfigured.
Procedure
To facilitate reconfiguration of CML server, the initial setup script can be executed manually using the following command.
sudo HOME=/var/local/virl2 /usr/local/bin/virl2-initial-setup.py --reconfigure
The script will start the initial setup wizard and allow you to reconfigure the settings of CML server. For details on the initial setup wizard, see Initial Set-up for standalone and Clustering Initial Setup for cluster deployments.
Note
There is a lightweight version that allows you to reconfigure the network settings of CML server.
sudo HOME=/var/local/virl2 /usr/local/bin/virl2-initial-setup.py --ipconfig
Below are some scenarios where the reconfiguration script can be used.
CML Lost its IP Address¶
At the event of a reboot or shutdown, especially when DHCP is configured for the management interface, CML server may fail to acquire an IP address. At this time, both the CML and System Administration Cockpit will not be accessible. To assign or reconfigure an IP address to CML server, use the KVM console of CML server, and run the reconfiguration script.
Procedure
Log into CML server using the KVM console.
sudo HOME=/var/local/virl2 /usr/local/bin/virl2-initial-setup.py --ipconfig
The script will start the initial setup wizard and should automatically populate the previous values.
Just complete the wizard without making any changes. For details on the initial setup wizard, see Initial Set-up for standalone and Clustering Initial Setup for cluster deployments.
The script will reconfigure the network settings of CML server and assign an IP address to the management interface. After the script completes, you should be able to access CML and System Administration Cockpit again.
Lost Connectivity to CML after Adding an External Interface¶
Configuring custom external connectivity may require adding a second interface to CML server. Each interface added to CML uses DHCP by default. If CML server was powered off to add the second interface and network segment used for external connectivity is configured with a DHCP server, when CML server is powered back on, the second interface will acquire an IP address and the underlying Ubuntu operating system may use the newly added interface as the default gateway.
Procedure
To verify, log into CML server using the KVM console and run the command.
$ ip route
The output should list the default routes and the newly added interface will have a lower metric. To regain access to CML, follow the next steps.
Power off CML server.
Disconnect the newly added interface by unchecking the “Connect at power on” option in the VM settings.
Power on CML server.
Log into System Administration Cockpit and navigate to the Networking tab.
Identify the newly added interface and change the IPv4 address from DHCP to Disabled.
Change IPv6 address from DHCP to Ignore.
Connect the newly added interface and proceed with custom bridge creation.
Note
In some cases, disconnecting the newly added interface may not resolve the issue, and it may be required to run the lightweight version of the reconfiguration script (–ipconfig) to re-wire the CML networking. Remember to select the correct interface for CML management. For details on the initial setup wizard, see Initial Set-up for standalone and Clustering Initial Setup for cluster deployments.
Note
As a preventive measure, after adding a new interface to CML server, do not check connect at power on and connected check boxes. Log into System Administration Cockpit and immediately disable DHCP on the interface before connecting the interface to CML server.
Lost Connectivity to CML after Creating a Custom Bridge¶
To complete the custom external connectivity configuration in CML, it is essential to create a single bridge or multiple bridges depending on the type of connection virtual nodes should establish to the outside world. See CML Training Videos on External Connectivity <https://learningnetwork.cisco.com/s/learning-plan-detail-standard?ltui__urlRecordId=a1c6e00000975VoAAI<ui__urlRedirect=learning-plan-detail-standard> for details on the different options for using custom external connectivity in CML.
Each bridge added to CML uses DHCP by default, If the custom external network has a DHCP server configured, the custom bridge will acquire an IP address. And on the next reboot/power cycle of CML server, the underlying Ubuntu operating system may use the newly added bridge as the default gateway.
Procedure
To regain access to CML, follow the next steps.
Power off CML server.
Disconnect the newly added interface by unchecking the “Connect at power on” option in the VM settings.
Power on CML server.
Log into System Administration Cockpit and navigate to the Networking tab.
Identify the newly added interface to CML server and recently created bridge.
Change the IPv4 address from DHCP to Disabled.
Change IPv6 address from DHCP to Ignore.
Connect the newly added interface to CML server.
Note
In some cases, disconnecting the newly added interface may not resolve the issue, and it may be required to run the lightweight version of the reconfiguration script (–ipconfig) to re-wire the CML networking. For details on the initial setup wizard, see Initial Set-up for standalone and Clustering Initial Setup for cluster deployments.
Note
As a preventive measure, after creating a new bridge, immediately disable DHCP on the bridge before adding an interface to the bridge.
Standalone to Cluster Controller Conversion¶
The CML reconfiguration script can be used for converting a CML standalone instance to a CML cluster controller. By default, the conversion will preserve the reference platform images, users and lab files. To preserve VM nodes, it is required to allow VM nodes to be managed by the cluster controller.
Procedure
Take a snapshot of the CML standalone instance if possible.
Add a second interface to the CML server for internal cluster network. See Cluster Requirements for details on the internal cluster network requirements.
Log in to System Administration Cockpit and navigate to the Terminal tab.
Stop CML services by running the following command.
sudo systemctl virl2.target
Run the reconfiguration script with the following command.
sudo HOME=/var/local/virl2 /usr/local/bin/virl2-initial-setup.py --reconfigure
The script will start the initial setup wizard and allow you to convert the CML standalone instance to a cluster controller. The script will prompt you to select cluster configuration, to allow VM nodes, to select network interface for the internal cluster network. Remember to make a note of the cluster secret. For details on the initial setup wizard, see Initial Set-up for standalone and Clustering Initial Setup for cluster deployments.
Note
If you do not allow VM nodes on the converted CML instance, the wizard will reject the conversion unless all VM nodes are wiped.
Follow the process documented in Clustering Initial Setup to add compute hosts to the cluster deployment.
Cluster Synchronization Issues¶
After doing CML maintenance or when the cluster is power cycled, the controller may fail to discover the compute hosts or vise versa.
Procedure
To verify that the cluster hosts are in sync, log into the CML UI and click the status bar at the bottom of the browser.
The CML status bar will display the status of the controller and compute hosts. If the status shows as red for any of the compute hosts, it indicates that those compute hosts are not synchronized with the controller.
To resolve the issue, log into the System Administration Cockpit of the affected compute hosts, restart CML services by clicking Restart CML Services tab and clicking Restart Services button.
If the issue persists, log into the System Administration Cockpit of the controller, restart CML services by clicking Restart CML Services tab and clicking Restart Services button.
If the issue persists, log into the System Administration Cockpit of the affected compute hosts and run the reconfiguration script with the following command.
sudo HOME=/var/local/virl2 /usr/local/bin/virl2-initial-setup.py --reconfigure
The script will start the initial setup wizard and should automatically populate the previous values.
Just complete the wizard without making any changes. For details on the initial setup wizard, see Initial Set-up for standalone and Clustering Initial Setup for cluster deployments.
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