Attaching a Network Interface

If your ECS requires multiple network interfaces, you can attach them to your ECS.

1. Log in to the management console.
2. Click in the upper left corner and select a region and project.
3. Under Computing, click Elastic Cloud Server.
4. Click the name of the ECS to which you want to attach a network interface.

   The ECS details page is displayed.

5. On the Network Interfaces tab, click Attach Network Interface.
6. Select either of the following methods to attach the network interface.
   • Use an existing network interface.
     1. (Optional) Search for the network interface by name, ID, or private IP address.
     2. In the network interface list, select the target one.
   • Create a new network interface.

     Set the subnet and security group for the network interface to be attached.

     • Subnet: the subnet that the network interface belongs to.
     • New Private IP Address: If you want to add a network interface with a specified IP address, enter an IP address into the New Private IP Address field.
     • Security Group: You can select multiple security groups. In such a case, the access rules of all the selected security groups will apply to the ECS.
     • IPv6 Address: This parameter is optional. It is available only if the primary network interface has an IPv4/IPv6 dual-stack address. In such a case, the extension network interface supports IPv6 addresses.
       • Automatically assign IP address: indicates that the system automatically assigns an IPv4/IPv6 dual-stack address to the extension network interface. In a VPC, an ECS can use an IPv6 address to access the dual-stack intranet. To access the Internet, you must select a shared bandwidth. Then, the ECS can use the IPv6 address to access the IPv6 Internet.
       • IPv6 not required: indicates that the system assigns only an IPv4 address to the extension network interface.
7. Click OK.

Some OSs cannot identify newly attached network interfaces. In this case, you need to manually activate the network interfaces. The following uses Ubuntu as an example to show how to activate network interfaces. Operations may vary depending on the operating system. You can refer to the corresponding OS documentation for assistance.

1. Log in to the management console.
2. Click in the upper left corner and select a region and project.
3. Under Computing, click Elastic Cloud Server.
4. Locate the row containing the target ECS and click Remote Login in the Operation column.

   Log in to the ECS.

5. Run the following command to view the network interface name:

   ifconfig -a

   In this example, the network interface name is eth2.

6. Run the following command to switch to the target directory:

   cd /etc/network

7. Run the following command to open the interfaces file:

   vi interfaces

8. Add the following information to the interfaces file:

   auto eth2

   iface eth2 inet dhcp

9. Run the following command to save and exit the interfaces file:

   :wq

10. Run either the ifup ethX command or the /etc/init.d/networking restart command to make the newly added network interface take effect.

    X in the preceding command indicates the serial number of the network interface, for example, ifup eth2.

11. Run the following command to check whether the network interface name obtained in step 5 is displayed in the command output:

    ifconfig

    For example, check whether eth2 is displayed in the command output.

    • If yes, the newly added network interface has been activated. No further action is required.
    • If no, the newly added network interface failed to be activated. Go to step 12.
12. Log in to the management console. On the ECS list page, locate the row that contains the target ECS and choose More > Restart in the Operation column.
13. Run ifconfig again to check whether the network interface name obtained in step 5 is displayed in the command output.
    • If yes, no further action is required.
    • If no, contact customer service.