Network Load Balancer (NLB)

The Network Load Balancing Manager is a stand-alone management application that you use to create and manage NLB clusters from a single management point

Configuring NLB on the First Host (Primary Application Server)

1. If you are configuring NLB on windows 2008 you need to check NLB driver version it should be (6.0.6001.22374), other wise install NLB patch (Windows6.0-KB960916-x64).
2. Launch the Network Load Balancing Manager (Start -> All Programs -> Administrative Tools).
3. Under the Cluster Menu option select New.

1. Enter the first node in the Cluster (Server1 IP).
2. Click Connect.
3. You will have the option to choose which network adapter you want to use; the NIC should be on the same subnet as the other servers in the NLB cluster
4. Click Next.
5. Enter the Priority ID as, 1 (each node in the NLB cluster should have a UNIQUE ID).
6. Make sure the correct adapter was selected under "Dedicated IP Address".
7. Select "Started" for the "Initial host state" (this tells NLB whether you want this node to participate in the cluster at start-up).
8. Click Next.
9. Click Add.

9.1 Enter the Cluster IP (192.168.1.250).

9.2 Enter the Subnet mask (255.255.255.0).

9.3 Click OK.

10. Click Next.
11. Select the IP Address for this cluster.
12. Enter the Full Internet Name (www.example.com).
13. Select Multicast as the "Cluster operation mode".
14. Click Next.
15. Click the Edit button.
16. Select the Single Host from the Filtering Mode and click OK.
17. Click the Finish button.
18. You should see a couple of things in the NLB Manager; this will let us know that this node successfully converged on our new Server1 NLB Cluster.

18.1 Make sure the node’s status changes to Converged.

18.2 Make sure you see a Succeeded message in the log window.

Configuring NLB on the Second Host (Secondary Application Server)

1. Right click the cluster name and select Add Host to Cluster.

1. Enter Server2 and Click Connect.
2. Select the network adapter you want to use for Load Balancing.
3. Click Next.
4. Enter the Priority ID as, 2 (each node in the NLB cluster should have a UNIQUE ID).
5. Make sure the correct adapter was selected under "Dedicated IP Address".
6. Select "Started" for the "Initial host state" (this tells NLB whether you want this node to participate in the cluster at start-up).
7. Click Next.
8. Click Finish.
9. You should see a couple of things in the NLB Manager; this will let us know that both nodes successfully converged on our new Server2 NLB Cluster.

9.1 Make sure that both nodes’ status changes to Converged.

9.2 Make sure each node has a unique host priority ID.

9.3 Make sure each node is started under initial host state.

9.4 Make sure you see a Succeeded message in the log window for the second node.

NLB Verification

• Go to the command prompt and type "wlbs query", as you can see HOST 1 and HOST 2 converged successfully on the cluster. This means things are working well.
• Ping each server locally and remotely.
• Ping the virtual IP locally and remotely – you should do this three times from each location. If you cannot ping remotely you may need to add a static ARP entry in your switches and/or routers where the host machines reside.
• 1 – Both nodes up
• 2 – Node 1 down
• 3 – Node 2 down

NOTE: Add the Virtual IP and the Virtual Hostname to the DNS Server to be able to Ping or Access the servers via the Virtual Hostname.