Microsoft Network Load Balancing (NLB) can be used to share a single IP address between two servers. This allows incoming FTP sessions to connect to either of the two MOVEit Automation computers. If both are running, NLB assigns the incoming session to one of the computers, typically the one with higher priority. If one computer is down, NLB assigns the incoming session to the working computer.
Overview
NLB does not allow outbound connections from both computers to use the same IP address. Thus, you should ensure that either:
Firewalls protecting hosts accessed by MOVEit Automation have rules allow incoming connections from either computer running MOVEit Automation
– or –
The firewall protecting MOVEit Automation uses Network Address Translation to make both computers look as if they have the same IP address
NLB is available on all editions of Windows 2008 and 2012.
Details
To use NLB, you take the following steps:
Decide on an IP address by which the cluster will be known. This should be different from the IP addresses of the individual MOVEit Automation computers in the cluster.
On one MOVEit Automation node, configure Windows Network Load Balancing as follows:
Use Network Connections | (connection name) | Properties | Internet Protocol (TCP/IP) | Properties | Advanced | Add... to add the cluster IP address to the list of addresses for your network adapter. If you have multiple adapters, use the one which will face the systems which you will be accessing.
Enable Windows Network Load Balancing on each server from the Network Connections | Properties dialog.
Run the Network Load Balancing Manager from Administrative Tools. You can ignore the warning:
Then you'll get the main window:
Choose Cluster | New to be prompted with the "Cluster Parameters" window.
Enter the external IP address (configured in Advanced TCP/IP Settings above) which the MOVEit Automation computers will share and choose Multicast for operation mode. Enter the subnet mask and domain name. Then choose Next.
Do not enter any information into the Cluster IP Addresses dialog. Simply choose Next.
Configure your inbound port settings. In some situations, sticking with the default of "all ports" will be sufficient, but you will want to configure specific ports if you are using remote control software or a remote copy of MOVEit Automation Admin to access each node in the MOVEit Automation cluster. A more reliable setup is to only add the inbound ports needed by your FTP server. (For example: FTP control port 21 and the passive FTP data ports). Once you have the proper list, choose Next.
At the Connect dialog, enter localhost and choose Connect. This will cause a list of network interfaces to appear. Select the external network interface and choose Next. (In the example below, there is only one interface.)
In the Host Parameters dialog, set the dedicated IP address to the main IP address of this adapter. Set an appropriate subnet mask. Leave the other parameters at their default values. Choose Finish to complete the setup.
On the other MOVEit Automation box, perform the following steps:
Enable Network Load Balancing, as above.
In Network Load Balancing Manager, use Cluster | Connect to Existing to bring up the Connect dialog.
Enter the IP address of the other computer that was configured above, and choose Connect. Select the cluster name corresponding to the one you just configured on the other computer, and choose Finish.
Right-click the name of the cluster, and choose Add Host To Cluster.
Enter "localhost" as the host name, and choose Connect. Select the name of the external interface, and choose Next.
Accept the defaults for the Host Parameters, and choose Finish.
Use Network Connections | (connection name) | Properties | Internet Protocol (TCP/IP) | Properties | Advanced | Add... to add the cluster IP address to the list of addresses for your network adapter.
You may need to reboot the systems to clear NLB errors due to temporary issues with recognizing the cluster IP address.
