Help Center/ Virtual Private Cloud/ FAQs/ Virtual IP Addresses/ Why Can't the Virtual IP Address Be Pinged After It Is Bound to an ECS NIC?
Updated on 2024-04-03 GMT+08:00
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Why Can't the Virtual IP Address Be Pinged After It Is Bound to an ECS NIC?

Symptom

After you bind a virtual IP address to an ECS NIC, you cannot ping the virtual IP address.

Troubleshooting

The issues here are described in order of how likely they are to occur.

Troubleshoot the issue by ruling out the causes described here, one by one.

Figure 1 Troubleshooting
Table 1 Troubleshooting

Possible Cause

Solution

Virtual IP address of the ECS NIC

See Virtual IP Address of the ECS NIC

Virtual IP address of the internal NIC of the ECS

See Virtual IP Address of the Internal NIC of the ECS

Security group or network ACL configuration

See Security Group or Network ACL Configuration

Virtual IP Address of the ECS NIC

Check whether the source/destination check of the NIC is disabled and whether a virtual IP address is bound to the NIC.
  1. Log in to the management console.
  2. Click Service List and click Elastic Cloud Server under Computing.
  3. In the ECS list, click the name of the ECS.
  4. On the displayed ECS details page, click the Network Interfaces tab.
  5. Ensure that Source/Destination Check is disabled.
  6. Ensure that an IP address is displayed for Virtual IP Address on the NIC details page.

    If there is no virtual IP address, click Manage Virtual IP Address. On the displayed IP Addresses tab, click Assign Virtual IP Address.

To check whether a virtual IP address has been configured, ifconfig will not work. Use ip address instead. For more information, see Binding a Virtual IP Address to an EIP or ECS.

Virtual IP Address of the Internal NIC of the ECS

The following uses Linux and Windows ECSs as examples to describe how to check whether an ECS NIC has a virtual IP address.

For a Linux ECS:
  1. Check if there is a NIC ethX:X:

    ifconfig

    Figure 2 Checking for NIC ethX:X

    The command output in the preceding figure contains a NIC ethX:X. 192.168.1.137 is its virtual IP address.

    • If the NIC ethX:X is there, the ECS NIC is correctly configured.
    • If the NIC ethX:X cannot be found, perform the following operations:
  2. If the command output does not contain a NIC ethX:X, switch to the /etc/sysconfig/network-scripts directory:

    cd /etc/sysconfig/network-scripts

  3. Run the following command to create and then modify the ifcfg-eth0:1 file:

    vi ifcfg-eth0:1

    Add the following NIC information to the file:

    BOOTPROTO=static
DEVICE=eth0:1
HWADDR=fa:16:3e:4d:5b:98
IPADDR=192.168.1.137
GATEWAY=192.168.1.1
NETMASK=255.255.255.0
ONBOOT=yes
ONPARENT=yes
  4. Press Esc, enter :wq!, and save the file and exit.
  5. Restart the ECS and run the ifconfig command to check whether the virtual IP address has been configured for the ECS.

For a Windows ECS:

  1. 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

    Figure 3 Checking whether the virtual IP address has been configured

    In the preceding command output, check whether the value of IPv4 Address (192.168.10.137) is the IP address of the ECS NIC.

    • If yes, the virtual IP address has been configured for the ECS NIC.
    • If no, perform the following operations:
  2. Choose Control Panel > Network and Internet > Network Connections. Right-click the corresponding local connection and then 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 displayed in Figure 3. For example, 192.168.10.41.
    Figure 4 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 configured in Figure 3. For example, 192.168.10.137.

    Figure 5 Configuring virtual IP address

Security Group or Network ACL Configuration

Check whether the ECS security groups and the network ACLs associated with the subnet used by the ECS NIC are blocking traffic.
  1. On the ECS details page, click the Security Groups tab and confirm that required security group rules have been configured for the virtual IP address. If the required security group rules have not been configured, click Change Security Group or Modify Security Group Rule to change the security group or modify the security group rules.
  2. Click Service List. Under Networking, click Virtual Private Cloud. In the navigation pane on the left of the network console, click Network ACLs and check whether the network ACL rules associated with the subnet used by the ECS NIC are blocking access to the virtual IP address.
Parent topic: Virtual IP Addresses