Set Up a Network Load Balancer

Prerequisites: The Network Load Balancer (NLB) needs a private network with targets (such as VM instances), to distribute the client sessions. The targets must be provisioned already, and the connection requests can come through the internet access element or a separate private network.

Create a NLB

  1. Add the NLB element by dragging it into the Workspace.

  2. Connect NLB. NLB element has two interfaces, "Northern" at the top and "Southern" at the bottom. The northern interface is the Listener that connects to the clients, and the southern interface is the Backend that connects to the targets. Connect the northern interface (Listener) to the internet access element or a private network.

  3. Connect the southern interface (Backend) to the private network containing the targets.

Provision a new NLB

An existing NLB can be modified at any time. Please note that the provisioning process cannot be undone. Your password may be required for editing some of the elements as an additional security measure.

Delete a NLB

If you need to delete the NLB, right-click the element and choose Delete.

Add a load balancer

The load balancers created in the DCD enable load balancing on several servers in the network using the round-robin method.

The load balancer receives an IP address from the DHCP. Alternatively, you can assign a reserved IP address to it via its NIC. All servers connected to the load balancer receive this IP address. Direct communication between the servers (via the load balancer network) is, therefore, not possible.

An additional management network is thus recommended for configuring servers with a load balancer. Configuration via the load balancer is hardly possible since the round-robin procedure prevents a targeted connection with certain servers.


  1. Drag the load balancer element from the palette into the workspace.

  2. Connect the load balancer to the required servers.

  3. Connect the load balancer to internet access.

  4. Set the properties of the load balancer by selecting the element in the workspace** and opening its properties in the Inspector > Settings:

    • Name: Enter a name.

    • Name (NIC): Enter a name for the NIC of the load balancer.

    • The MAC address will be assigned automatically upon provisioning and cannot be changed.

    • Primary IP: The primary IP address is automatically assigned by the IONOS DHCP server. You can, however, enter an IP address for manual assignment by selecting one of the reserved IP addresses from the drop-down list. Private IP addresses (according to RFC 1918) must be entered manually.

    • DHCP: It is often necessary to run a DHCP server in your virtual data center (e.g., PXE boot for fast rollout of VMs). If you use your own DHCP server, clear this check box so that the IONOS DHCP server does not reassign your IPs.

    • In the Balanced NICs tab, you can check which servers are connected to the load balancer through which NIC.

    • (Optional) Make further changes to your data center.

  1. Provision your changes.

The load balancer is now active according to your settings.

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