Next Steps

This section provides some additional configuration specific to Cumulus VX and shows some basic commands you can try to get started with Cumulus Linux. Additional resources for further reading and more advanced configuration are also provided.

Perform Additional Configuration

To provide easier access in video-focused hypervisors (such as VirtualBox), Cumulus VX is configured by default to redirect the grub menu and the kernel output to the video console. Follow the steps below to send both the grub menu and the kernel output back to the serial console.

If the VM has not been booted:

  1. Interrupt the boot process at the GRUB prompt.

  2. Modify the Linux command line directly, removing all references to the console entries:

    Original Version:


    Configured Version:


    The example images above are for the ONIE-RESCUE entry, not the standard boot entry. The configuration process is the same for both entries.

  3. Start the VM.

If the VM is already running:

  1. Run the following commands as the sudo user:

    cumulus@switch:~$ sed -i 's/^#//' /etc/default/grub.d/00-installer-defaults.cfg
    cumulus@switch:~$ sed -r -i '/^GRUB_CMDLINE_LINUX=/ s/(console=ttyS0,115200n8) (console=tty0)/\2 \1/' /etc/default/grub
    cumulus@switch:~$ update-grub 
  2. Restart the VM to implement the change.

Try Basic Commands

After you have configured the Cumulus VX instances and performed additional configuration, use the wider Cumulus Linux documentation suite to help you configure and test features, and fine tune the network topology.

This section provides some basic commands to get you started. You can run the commands on each VM to see system information, as well as interface and LLDP details and to change the hostname of a switch.

To get information about the switch itself, run the net show system command:

cumulus@switch:~$ net show system
Cumulus VX
Cumulus Linux 3.5.0
Build: Cumulus Linux 3.5.0
Uptime: 4:29:09.270000

To show every available interface that is physically UP, run the net show interface command:

cumulus@switch:~$ net show interface
       Name    Master    Speed    MTU    Mode           Remote Host       Remote Port    Summary
-----  ------  --------  -------  -----  -------------  ----------------  -------------  -------------------------------------
UP     lo                N/A      65536  Loopback                                        IP:,, ::1/128
UP     eth0              1G       1500   Mgmt                                            IP:
UP     swp1              1G       1500   Interface/L3   CumulusVX-spine1  swp1           IP:
UP     swp2              1G       1500   Interface/L3   CumulusVX-spine2  swp1           IP:
UP     swp3              1G       1500   Interface/L3                                    IP:
ADMDN  swp4              N/A      1500   NotConfigured
ADMDN  swp5              N/A      1500   NotConfigured
ADMDN  swp6              N/A      1500   NotConfigured
ADMDN  swp7              N/A      1500   NotConfigured 

To get topology verification, run the net show lldp command.

The example output below shows the two-leaf/two-spine Cumulus VX network topology from CumulusVX-leaf1, where local port swp1 is connected to remote port swp1 on CumulusVX-spine1 and local port swp2 is connected to remote port swp1 on CumulusVX-spine2.

cumulus@switch:~$ net show lldp
LocalPort    Speed    Mode          RemotePort    RemoteHost        Summary
-----------  -------  ------------  ------------  ----------------  ---------------
swp1         1G       Interface/L3  swp1          CumulusVX-spine1  IP:
swp2         1G       Interface/L3  swp1          CumulusVX-spine2  IP:

To change the hostname, run the net add hostname command.

This command updates both the /etc/hostname and /etc/hosts files.

cumulus@switch:~$ net add hostname <hostname>

Further Information

Check out these community articles and the rest of the Cumulus Linux documentation: