W2K8 R2 – Configuring Network Load Balancing

W2K8 R2 – Configuring Network Load Balancing

Introduction

This article provides the steps required to install and configure Microsoft Network Load Balancing on a pair of Windows 2008 R2 servers with Service Pack 1 installed.

Microsoft Network Load Balancing is most commonly used to load balance web servers and this article will use two Windows 2008 R2 servers with Internet Information Services installed for testing.

Prerequisites

In order to install and configure Microsoft Network Load Balancing the following prerequisites must be met :-

  • At least two Windows 2008 R2 servers
  • At least one network card dedicated for Load Balancing on each server
  • Five available IP addresses
  • All servers participating in the NLB Cluster must reside on the same subnet

Microsoft best practices for installing Microsoft Network Load Balancing require at least one dedicated network card for Load Balancing on each server in the cluster meaning that each server requires two IP addresses assigning.
A fifth IP address is also required for the NLB cluster VIP which is used for connection to the NLB clustered services.

Configuring The Load Balancing Network Cards

The first step is to configure the dedicated load balancing Network Card on each of the servers.

Microsoft best practices are to only use TCP/IP on the load balancing Network Card and as an additional modification I disable any unecessary items on the Network Card like Client for Microsoft networks, IPv6 if not in use, and the Link-Layer Topology drivers.  Alongside these modifications I also disable DNS registration for the load balancing Network Card.

To perform these modifications perform the following steps :-

  • Open the Properties for the load balancing Network Card
  • Under the Connection uses the following items section disable the following items :-

Client for Microsoft Networks
Qos Packet Scheduler
File and Print Sharing for Microsoft Networks
Internet Protocol Version 6 (TCP/IPv6)
Link-Layer Topology Discovery Mapper I/O Driver
Link-Layer Topology Discovery Responder

  • Edit the Properties for Internet Protocol Version 4 (TCP/IPv4)
  • Configure the IP Address and Subnet for the Network Card as normal but Do Not configure the Default Gateway or DNS Servers.
  • Click on the Advanced button
  • Click on the DNS tab and disable the Register this connection’s addresses in DNS option and then click on OK
  • Click on OK to apply the settings and then OK again to close the Network Card properties

Installing The Network Load Balancing Feature

The next step is to install the Network Load Balancing Feature on the servers.  To install the Network Load Balancing Feature on the servers perform the following steps :-

  • Open the Server Manager and click on Features in the Left Hand pane
  • Click on the Add Features link
  • Select the Network Load Balancing feature from the list and then click on Next to continue
  • At the Confirmation screen click on Install
  • At the Results screen click on Close to complete the installation

Creating The Network Load Balancing Cluster

The next step is to configure the Network Load Balancing Feature on the servers.  To configure the Network Load Balancing Feature on the servers perform the following steps :-

  • Open the Network Load Balancing Manager console on the first server
  • Click on Cluster and then select New
  • In the Host box enter the name of the First Server and click onConnect
  • From the Interfaces Avaliable for configuring a new cluster section select the Load Balancing Network Card on the server
  • Click on Next to continue
  • On the New Cluster: Host Parameters screen click on Next to continue
  • On the New Cluster: Cluster IP Addresses screen click on Add
  • When prompted enter the IP Address and Subnet for the Cluster VIPand then click on OK
  • On the New Cluster: Cluster Parameters screen enter the Full Internet Name for the cluster
  • Ensure the Cluster Operation Mode is set to Unicast and then click on Next to continue
  • On the New Cluster: Port Rules screen click on Finish to continue

Joining The Second Server To The Cluster

The final step is to join the second server to the Network Load Balancing Cluster.  To join the second server to the Network Load Balancing Cluster perform the following steps :-

  • Open the Network Load Balancing Manager console on the second server
  • Click on Cluster and then select Connect To Existing
  • In the Host box enter the name of the First Server and click on Connect
  • Ensure that the Cluster set up in the previous section is displayed in the Clusters screen and then click on Finish
  • Right Click on the Cluster Name in the Left Hand pane and select Add Host to Cluster
  • In the Host box enter the name of the Second Server and click on Connect
  • From the Interfaces Avaliable for configuring a new cluster section select the Load Balancing Network Card on the server
  • Click on Next to continue
  • On the New Cluster: Host Parameters screen click on Next to continue
  • On the New Cluster: Port Rules screen click on Finish to continue