NLB: Windows Installation and Configuration 2012R2 / 2016 – Network Load Balancing

Presentation of NLB

Network Load Balancing (NLB) is a feature built into Windows that allows the implementation of load balancing at the network level. It is often used with IIS / FTP / RDS.

NLB works with a virtual IP address that is available to all hosts in the cluster.

NLB supports up to 32 nodes on the same cluster, according to Microsoft best practices it is advisable to create clusters of maximum 8 nodes.

The NLB feature relies on network-level distribution, one of the limitations of this solution is that the heatbeats tests monitor whether the hosts are online and not the service. If the web service of one of the hosts is non-functional but the host responds to the HB, requests will be sent to the host.

Representation of an NLB cluster in monodiffussion:
Cluster NLB


Setting up a Network Load Balancing Cluster you need:

  • At least two servers with the same service installed (for this lab I used two IIS web servers) and two network cards. A card will be for server management and a dedicated NLB cluster card. If the NLB cluster is configured in Multidiffussion it is not necessary to have two network cards.
  • At least 3 IPs: 1 IP for the cluster that will be virtual and an IP address for each node

If your servers are under Hyper-V, you must activate the MAC address spoofing on network adapters dedicated to the NLB cluster.
Hyper-v carte reseau

Modes of transmission

Unicast: the default mode, it will disable the MAC address of the network card and replace it with an identical virtual address on all nodes.

Multicast: recommended mode, it can be used with one or more network cards. With this mode, the network adapter will have two MAC addresses, the one on the network adapter and the virtual MAC address of the cluster.

Related Posts

Failover Clustering Windows 2016/2019 – Installation and Configuration

Presentation The failover clustering feature ensures high availability of a service by using multiple servers (nodes) that can make it work. Some examples of services that can be used with the Failove

Deploy Windows with MDT and WDS

In this tutorial, I will explain how to use the Microsoft Deployment Toolkit (MDT) and Windows Deployment Services (WDS) pairing to deploy Windows images (7/8. (1) / 10) using the PXE boot. Prerequisi

How to deploy an RDS Farm Windows 2012R2/2016/2019

In this tutorial, we will see how to set up a RDS farm in Windows 2012R2 / 2016/2019 with the following features: Remote Desktop Session Host (x2)Service broker for the distribution of connectionsSett