Setting the NIC to DHCP

Scenarios

If a private image is created from an ECS or external image file and the VM where the ECS or external image file is located is configured with a static IP address, you need to change the NIC attribute to DHCP so that the new ECSs created from the private image can dynamically obtain an IP address.

The configuration method varies depending on OSs.

Note

When registering an external image file as a private image, configure DHCP on the VM where the external image file is located. You are advised to configure DHCP on the VM and then export the image file.

Prerequisites

You have logged in to the ECS used to create a Windows private image.

For details about how to log in to an ECS, see Elastic Cloud Server User Guide.

Procedure

This section uses Ubuntu 16.04 as an example to describe how to query and configure NIC attributes of an ECS.

  1. Run the following command on the ECS to open the /etc/network/interfaces file using the vi editor and query the IP address obtaining mode:

    vi /etc/network/interfaces

    • If DHCP has been configured on all NICs, enter :q to exit the vi editor.

      auto lo
      iface lo inet loopback
      auto eth0
      iface eth0 inet dhcp
      
      auto eth1
      iface eth1 inet dhcp
      
    • If static IP addresses are set on the NICs, go to 2.

      auto lo
      iface lo inet loopback
      auto eth0
      #iface eth0 inet dhcp
      iface eth0 inet static
      address 192.168.1.109
      netmask 255.255.255.0
      gateway 192.168.1.1
      
  2. Press i to enter editing mode.

  3. Delete the static IP address configuration and configure DHCP for the NICs.

    You can insert a number sign (#) in front of each line of static IP address configuration to comment it out.

    auto lo
    iface lo inet loopback
    auto eth0
    iface eth0 inet dhcp
    

    If the ECS has multiple NICs, you must configure DHCP for all the NICs.

    auto lo
    iface lo inet loopback
    auto eth0
    iface eth0 inet dhcp
    auto eth1
    iface eth1 inet dhcp
    
  4. Press Esc, enter :wq, and press Enter.

    The system saves the configuration and exits the vi editor.