User Accounts

By default, Cumulus Linux has two user accounts: cumulus and root.

The cumulus account:

• Uses the default password cumulus. You must change the default password when you log into Cumulus Linux for the first time.
• Is a user account in the sudo group with sudo privileges.
• Can log in to the system through all the usual channels, such as console and SSH.
• Along with the cumulus group, has both show and edit rights for NVUE.

The root account:

• Has the default password disabled by default
• Has the standard Linux root user access to everything on the switch
• The disabled password prevents you from using SSH, telnet, FTP, and so on, to log in to the switch.

You can add additional user accounts as needed. Like the cumulus account, these accounts must use sudo to execute privileged commands; be sure to include them in the sudo group. For example:

cumulus@switch:~$ sudo adduser NEWUSERNAME sudo

To access the switch without a password, you need to boot into a single shell/user mode.

NVUE Command Access

You can control local user account access to NVUE commands by changing the Linux group membership for a user. Use the following groups to set the permissions for local user accounts. To add users to these groups, use the useradd(8) or usermod(8) commands:

Enable Remote Access for the root User

The root user does not have a password and cannot log into a switch using SSH. This default account behavior is consistent with Debian. To connect to a switch using the root account, you can do one of the following:

• Generate an SSH key
• Set a password

Generate an SSH Key for the root Account

1. In a terminal on your host system (not the switch), check to see if a key already exists:

   root@host:~# ls -al ~/.ssh/
   

   The name of the key is similar to id_dsa.pub, id_rsa.pub, or id_ecdsa.pub.

2. If a key does not exist, generate a new one by first creating the RSA key pair:

   root@host:~# ssh-keygen -t rsa
   

3. At the prompt, enter a file in which to save the key (/root/.ssh/id_rsa). Press Enter to use the home directory of the root user or provide a different destination.

4. At the prompt, enter a passphrase (empty for no passphrase). This is optional but it does provide an extra layer of security.

5. The public key is now located in /root/.ssh/id_rsa.pub. The private key (identification) is now located in /root/.ssh/id_rsa.

6. Copy the public key to the switch. SSH to the switch as the cumulus user, then run:

   cumulus@switch:~$ sudo mkdir -p /root/.ssh
   cumulus@switch:~$ echo <SSH public key string> | sudo tee -a /root/.ssh/authorized_keys
   

Set the root User Password

1. Run the following command:

   cumulus@switch:~$ sudo passwd root
   

2. Change the PermitRootLogin setting in the /etc/ssh/sshd_config file from without-password to yes.

   cumulus@switch:~$ sudo nano /etc/ssh/sshd_config
   ...
   # Authentication:
   LoginGraceTime 120
   PermitRootLogin yes
   StrictModes yes
   ...  
   

3. Restart the ssh service:

   cumulus@switch:~$ sudo systemctl reload ssh.service