Linux and Unix scanning requirements

Network Discovery scans Linux and Unix computers over SSH. Other protocols, such as SNMP, can return some data, but SSH gives the most detailed results.

To scan a Linux or Unix computer, you need SSH enabled and a discovery credential for an account that can run a small set of read-only commands.

Requirements

Every Linux or Unix computer you scan must meet these requirements:

• SSH: SSH must be enabled. We recommend OpenSSH. Network Discovery connects over TCP 22.
• Credential: An SSH discovery credential for an account that can at least run the uname command. Full root access isn't required, but an account with sudo rights is recommended, since some commands run through sudo.

Network Discovery runs a set of read-only commands, such as uname, to collect the operating system, processor, memory, and installed software. Both password and certificate-based SSH authentication are supported.

Verify and enable SSH

1. Check whether OpenSSH is installed. Use your package manager or run one of these commands:

   • Debian, Linux Mint, Ubuntu: dpkg -s openssh
   • Fedora, Red Hat: rpm -q openssh
   • Manjaro (Arch): pacman -Q openssh

2. Install the OpenSSH server if it isn't present. Use your package manager or run one of these commands:

   • Debian, Linux Mint, Ubuntu: sudo apt-get install openssh-server
   • Fedora, Red Hat: sudo yum install openssh
   • Manjaro (Arch): sudo pacman -S openssh

3. Enable SSH to start automatically, then start the service:

   sudo systemctl enable sshd
   sudo systemctl start sshd
   

4. Verify that SSH is running. If the command returns output, SSH is active:

   ps -e | grep sshd
   

Next steps

• Create discovery credentials for the Linux and Unix computers you want to scan.
• Create a Network Discovery action to define what to scan, when, and with which credentials.