Configure a NLB

Select the NLB element to open its properties in the Inspector pane on the right. The name of the NLB and the number of balanced NICs are displayed at the top of the pane.
Configuration options are grouped under three tabs: Settings, Forwarding rules, and Private IPs.
Configuration of a network load balancer


NLB Listener accepts connections from clients through an exposed IP address (Primary IPv4) and configured listener port. The Listener interface can also monitor additional IPs (Add IP). Listener IPs can be private (for local networks) or public (exposed to the Internet). Public IPs must be reserved before they can be used. For more information, see Listener.
You can fill in the following details in Settings:
  • Name: You can use the default or enter a new name for the NLB.
  • By clicking on Load Balancer you can show or hide the Primary IPv4 and Add IP settings.
  • Primary IPv4: Assign the first (primary) Listener IP address. For Automatic, no entry is required; a private primary Listener IP address will be assigned automatically on provisioning.
  • For private IP, enter a private IP address directly. For public IP, Public IP is required for an NLB that is connected to the Internet.
Public IPs must first be reserved. Reserve public IPs using the IP Manager in the main menu.
  • Add IP: Assign one or more additional Listener IPs; additional IPs are optional. For private IP, choose Add private IP and enter the address directly.
  • Reserve public IP: Available only when no reserved public IPs exist. Click Add IP > Reserve public IP, enter a name for the IP block, the number of IPs to be reserved, and click Reserve IPs.
  • Public IP: Public IPs must already have been reserved. Click Add IP and choose a reserved IP block name from the drop-down list, then select a reserved IP address.
  • Multiple IPs: Use Add IP again to add as many IPs as needed. All added private and public IPs are listed below the IP settings.
Configuration changes are saved only once the VDC is provisioned.

Forwarding rules

Forwarding rules define how client traffic is distributed to the targets. More than one forwarding rule can be created for the same load balancer.
In Forwarding rules, you can enter a name for this forwarding rule, choose a load balancing algorithm from the drop-down list, set the protocol to TCP (it cannot be changed), select an IP address for Listener IP, enter the Listener port directly, or select one from the list.

Create a rule

  • Click Create to create the rule.
  • Click the name of the rule to expand or collapse its settings.
  • Click Add target to add targets.
  • Choose Health check to configure Health check connection settings for this forwarding rule.
  • Use Add forwarding rule again to add as many rules as needed. All added rules are listed in Inspector under the Forwarding rules tab.

Private IPs

NLB backend exposes a private IP to targets as the source of client traffic. The backend IP address is configurable and defaults to x.x.x.225. Backend IPs are listed in the NLB Inspector under the Private IPs tab.

Adding and deleting IPs

  • It is best to use the default IP address in most cases. To change an already-provisioned IP, delete the existing IP address first and then add a new one.
  • Click the down arrow and select Remove IP to delete the IP address.
  • Enter an IP address in CIDR notation (e.g., and click Add IP. The new IP must be private and match the subnet mask of the Target network.
  • Use Add IP again to add as many private IPs as needed. All added IPs are listed under the Private IPs.