The purpose of a backup network

The majority of the datacenters that are build up using the modern datacenter approach are committed to both redundancy but also smart designs regarding providing uptime for the hosted services.

Providing a dedicated backup network that the backup traffic can use and rely on is a good strategy since it will offload the primary network architecture and not be dependent of the network hardware that builds up the production network.

There are some prerequisites for enabling a backup network:

• Secondary network card
• Enabling name resolution 
• Verifying network connectivity 

The configuration for setting up a backup network is made via PowerShell but first you must have a secondary network card installed that is configured with the IP addresses that is a member of the backup network subnet.

The next step is to verify name resolution, alter the HOST file on both the production server and also the DPM server and enter the NetBIOS name for the servers involved.

Verify that you can ping the IP address for the backup network on the DPM server from the production environment and also via NetBIOS name.

To configure the backup network you open the DPM Management Shell and use the PowerShell CMDLET called Add-BackupNetworkAddress.

To configure the DPM server to use the dedicated network of 10.1.1.0/24 enter the following syntax:
Add-BackupNetworkAddress –Address 10.1.1.0/24 –DPMServer DPM1 –SequenceNumber 1

The three switched are:

• Address
• DPMServer
• SequenceNumber

The Address switch provides the address for the backup network. The DPMServer provides the NetBIOS name for the DPM server. With the SequenceNumber switch you provide the primary backup network and also the failover backup network.

The DPM agent will verify its XML configuration and understand what network it should use as its primary backup network. Normal communication between the DPM agent and the DPM server will still travel over the production network. If the backup network connectivity fails the DPM agent can be setup using also a secondary backup network that will be a failover network for that traffic. The failover network is something that you must configure for it to work.