Sometimes the network configuration does not appear during the Debian installation or IP addresses and routes change. In this case, you have to configure the network manually:

  1. Before editing the file, check the name of the network card being used by entering the following command:
    ip –h addr
  • This command replaces the previous ifconfig command.
  • The previous notation for eth0 changes to ens32, eth1 to ens33 and so on.
  1. Example: Open the file vi /etc/network/interfaces
    # This file describes the network interfaces available on your system

    # and how to activate them. For more information, see interfaces(5).
    # The loopback network interface
    auto lo

    iface lo inet loopback
    # The primary network interface
    allow-hotplug ens32
    iface ens32 inet static
  1. Adjust the file.
  1. If the file is created again, restart the system.
  1. If changes are made to the /etc/network/interfaces file, restart the system with the following command: sudo init 6