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How Do I Handle the Layer 2 or Layer 3 Network Communication Failure?

  1. Check whether the ECS has obtained an IP address.

    Log in to the ECS, and run the ifconfig or ip address command to check the ECS NIC IP address information. The ipconfig command applies only to Windows ECSs.

  2. If the ECS does not have an IP address, check whether DHCP has been enabled for the required subnet.

    Switch to the subnet details page and check whether the DHCP function has been enabled.

  3. If the ECS has an IP address, check whether the security group rules and firewall rules allow the required traffic to pass through.
    1. Check the security group rules.

      Obtain the security group used by the ECS NIC from the ECS details page. The security group rule that allows the ECS to access the required subnet has been configured for the security group.

    2. Check the firewall rules.

      If you can configure the firewall on the VPC console, confirm that the firewall rules allow traffic from the required subnets to pass through.

Parent topic: Connectivity