Binding a Virtual IP Address to an Instance or EIP

You can bind a virtual IP address to an instance or EIP.

• Bind a virtual IP address to an instance. You can:
  • Bind one or more virtual IP addresses to an instance.
  • Bind a virtual IP address to multiple instances.
• Bind a virtual IP address to an EIP to enable Internet communications.

It is recommended that a maximum of eight virtual IP addresses be bound to an ECS. If an ECS has multiple virtual IP addresses, each virtual IP address is used by a specific service. If there are too many services, the ECS may become overloaded and compromise user experience.

1. Log in to the management console.
2. Click in the upper left corner and choose Network > Virtual Private Cloud.

   The Virtual Private Cloud page is displayed.

3. In the navigation pane on the left, choose Virtual Private Cloud > Subnets.

   The Subnets page is displayed.

4. In the subnet list, locate the target subnet and click its name.

   The subnet details page is displayed.

5. On the IP Addresses tab, bind an EIP to the virtual IP address:
   1. Locate the row that contains the virtual IP address and click Bind to EIP in the Operation column.

      The Bind to EIP dialog box is displayed.

   2. Select an EIP and click OK.

      In the virtual IP address list, you can view the bound EIP.

6. On the IP Addresses tab, bind a server to the virtual IP address:
   1. Locate the row that contains the virtual IP address and click Bind to Server in the Operation column.

      The Bind to Server dialog box is displayed.

   2. Select a server and click OK.

      In the virtual IP address list, you can view the bound server.

      • After you bind one or more virtual IP addresses to an ECS on the console, you need to manually configure the virtual IP addresses on the ECS. For details, see Configuring a Virtual IP Address for an ECS.

After you bind one or more virtual IP addresses to an ECS on the console, you must log in to the ECS to manually configure these virtual IP addresses.

The following OSs are used as examples here. For other OSs, see the help documentation on their official websites.

• Linux: CentOS 8.2 64bit and Ubuntu 22.04 server 64bit
• Windows: Windows Server

The following uses CentOS 8.2 64bit as an example.

1. Obtain and take a note of the network interface that the virtual IP address is to be bound and the connection of the network interface:

   nmcli connection

   Information similar to the following is displayed:

   [root@ecs-centos ~]# nmcli connection
   NAME         UUID                                  TYPE      DEVICE 
   System eth0  5fb06bd0-0bb0-7ffb-45f1-d6edd65f3e03  ethernet  eth0   
   System eth1  9c92fad9-6ecb-3e6c-eb4d-8a47c6f50c04  ethernet  --     
   System eth2  3a73717e-65ab-93e8-b518-24f5af32dc0d  ethernet  --     
   System eth3  c5ca8081-6db2-4602-4b46-d771f4330a6d  ethernet  --     
   System eth4  84d43311-57c8-8986-f205-9c78cd6ef5d2  ethernet  -- 
   
   

   The command output in this example is described as follows:

   • eth0 in the DEVICE column indicates the network interface that the virtual IP address is to be bound.
   • System eth0 in the NAME column indicates the connection of the network interface.
2. Add the virtual IP address for the connection:

   nmcli connection modify "connection-name-of-the-network-interface" +ipv4.addresses virtual-IP-address

   Configure the parameters as follows:

   • connection-name-of-the-network-interface: The connection name of the network interface obtained in 1. In this example, the connection name is System eth0.
   • virtual-IP-address: The virtual IP address to be added. If you add multiple virtual IP addresses at a time, separate every two with a comma (,).

   Example commands:

   • Adding a single virtual IP address: nmcli connection modify "System eth0" +ipv4.addresses 192.168.0.22
   • Adding multiple virtual IP addresses: nmcli connection modify "System eth0" +ipv4.addresses 192.168.0.22,192.168.0.23

3. Make the configuration in 2 take effect:

   nmcli connection up "connection-name-of-the-network-interface"

   In this example, run the following command:

   nmcli connection up "System eth0"

   Information similar to the following is displayed:

   [root@ecs-centos ~]# nmcli connection up "System eth0"
   Connection successfully activated (D-Bus active path: /org/freedesktop/NetworkManager/ActiveConnection/2)
   
   

4. Check whether the virtual IP address has been bound:

   ip a

   Information similar to the following is displayed. In the command output, virtual IP address 192.168.0.22 is bound to network interface eth0.

   [root@ecs-centos ~]# ip a
   1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
       link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
       inet 127.0.0.1/8 scope host lo
          valid_lft forever preferred_lft forever
       inet6 ::1/128 scope host 
          valid_lft forever preferred_lft forever
   2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
       link/ether fa:16:3e:54:ac:fa brd ff:ff:ff:ff:ff:ff
       inet 192.168.0.22/32 scope global noprefixroute eth0
          valid_lft forever preferred_lft forever
       inet 192.168.0.78/24 brd 192.168.0.255 scope global dynamic noprefixroute eth0
          valid_lft 315359994sec preferred_lft 315359994sec
       inet6 fe80::f816:3eff:fe54:acfa/64 scope link 
          valid_lft forever preferred_lft forever
   
   

   Note

   After the preceding configurations are complete, the configurations will not be lost after the ECS is restarted.

   To delete an added virtual IP address, perform the following steps:

   1. Delete the virtual IP address from the connection of the network interface:

      nmcli connection modify "connection-name-of-the-network-interface" -ipv4.addresses virtual-IP-address

      To delete multiple virtual IP addresses at a time, separate every two with a comma (,). Example commands are as follows:

      • Deleting a single virtual IP address: nmcli connection modify "System eth0" -ipv4.addresses 192.168.0.22
      • Deleting multiple virtual IP addresses: nmcli connection modify "System eth0" -ipv4.addresses 192.168.0.22,192.168.0.23

   2. Make the deletion take effect by referring to 3.

The following uses Ubuntu 22.04 server 64bit as an example. If the ECS runs Ubuntu 22 or Ubuntu 20, perform the following operations:

1. Obtain and take a note of the network interface that the virtual IP address is to be bound:

   ifconfig

   Information similar to the following is displayed. In this example, the network interface with the virtual IP address bound is eth0.

   root@ecs-X-Ubuntu:~# ifconfig
   eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
           inet 172.16.0.210  netmask 255.255.255.0  broadcast 172.16.0.255
           inet6 fe80::f816:3eff:fe01:f1c3  prefixlen 64  scopeid 0x20<link>
           ether fa:16:3e:01:f1:c3  txqueuelen 1000  (Ethernet)
           RX packets 43915  bytes 63606486 (63.6 MB)
           RX errors 0  dropped 0  overruns 0  frame 0
           TX packets 3364  bytes 455617 (455.6 KB)
           TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
   ...
   
   

2. Switch to the /etc/netplan directory:

   cd /etc/netplan

3. Add a virtual IP address to the network interface.
   1. Open the configuration file 01-netcfg.yaml:

      vim 01-netcfg.yaml

   2. Press i to enter the editing mode.
   3. In the network interface configuration area, add a virtual IP address.

      In this example, add a virtual IP address for eth0:

      addresses:

      - 172.16.0.26/32

      The file content is as follows:

      network:
          version: 2
          renderer: NetworkManager
          ethernets:
              eth0:
                  dhcp4: true
                  addresses:
                  - 172.16.0.26/32
              eth1:
                  dhcp4: true
              eth2:
                  dhcp4: true
              eth3:
                  dhcp4: true
              eth4:
                  dhcp4: true
      
      

   4. Press Esc, enter :wq!, save the configuration, and exit.
4. Make the configuration in 3 take effect:

   netplan apply

5. Check whether the virtual IP address has been bound:

   ip a

   Information similar to the following is displayed. In the command output, virtual IP address 172.16.0.26 is bound to network interface eth0.

   root@ecs-X-Ubuntu:/etc/netplan# ip a
   ...
   2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
       link/ether fa:16:3e:01:f1:c3 brd ff:ff:ff:ff:ff:ff
       altname enp0s3
       altname ens3
        inet 172.16.0.26/32 scope global noprefixroute eth0 
          valid_lft forever preferred_lft forever
       inet 172.16.0.210/24 brd 172.16.0.255 scope global dynamic noprefixroute eth0
          valid_lft 107999971sec preferred_lft 107999971sec
       inet6 fe80::f816:3eff:fe01:f1c3/64 scope link 
          valid_lft forever preferred_lft forever
   
   

   Note

   After the preceding configurations are complete, the configurations will not be lost after the ECS is restarted.

   To delete an added virtual IP address, perform the following steps:

   1. Open the configuration file 01-netcfg.yaml and delete the virtual IP address of the corresponding network interface by referring to 3.
   2. Make the deletion take effect by referring to 4.

The following operations use Windows Server as an example.

1. In Control Panel, click Network and Sharing Center, and click the corresponding local connection.
2. On the displayed page, click Properties.
3. On the Network tab page, select Internet Protocol Version 4 (TCP/IPv4).
4. Click Properties.
5. Select Use the following IP address and set IP address to the private IP address of the ECS, for example, 10.0.0.101.

   Figure 1 Configuring a private IP address

   
   
6. Click Advanced.
7. On the IP Settings tab, click Add in the IP addresses area.

   Add the virtual IP address, for example, 10.0.0.154.

   Figure 2 Configuring a virtual IP address

   
   
8. Click OK.
9. In the Start menu, open the Windows command line window and run the following command to check whether the virtual IP address has been configured:

   ipconfig /all

   In the command output, IPv4 Address is the virtual IP address 10.0.0.154, indicating that the virtual IP address of the ECS's network interface has been correctly configured.