Using Backup Network Address

Using Backup Network Address

Updated: April 21, 2010

Applies To: System Center Data Protection Manager 2010

Data Protection Manager 2007 (DPM) allows you to configure a backup network address to ensure that DPM backups do not slow down your primary network. The backup network address is created when you put separate network adapters on the DPM server and the protected servers and connect them through a separate LAN. As a result, backup data traffic does not impact the primary network.

You can set up your backup network address using DPM 2007 Management Shell (PowerShell) cmdlets.

Setting up your network

Before you can set up a backup network address, you need to:

Ensure that the name resolution of the protected server on the DPM server can resolve the backup address of the protected server and vice versa.
Configure the backup subnet and the corresponding subnet mask using Add-BackupNetworkAddress.

Note
The subnet should cover the entire range of network addresses for the DPM server and the servers you intend to protect.
Restart the DPM agent on the DPM server and the protected computers. It may cause ongoing tasks to fail. Post a restart, watch out for alerts, and perform the recommended actions, if needed.

Note
The subnet should cover the entire range of network addresses for the DPM server and the servers you intend to protect.

Example

This example details the process of setting up a backup network address for a DPM server protecting another server. All names and addresses are hypothetical and for illustration only.

The existing backup setup consists of dpm.x.y.com protecting ps.x.y.com. Name lookup using “nslookup” on either server returns the following IPs (that is, each IP address is visible to each node):

Note
The name lookups must be performed on the FQDNs; for example, “nslookup ps.x.y.com”.

Server	NIC address
DPM server (dpm.x.y.com)	10.10.12.89
Protected computer (ps.x.y.com)	10.10.12.90

Now, to set up a backup network, another NIC is added to each of the above servers and connected to another network such as 192.168.1.0/24 with a corresponding subnet mask 255.255.255.0. When the network and NICs are configured, the name lookup using “nslookup” returns two addresses per server as given below.

Server	Primary NIC address	Backup NIC address
DPM server	10.10.12.89	192.168.1.23
Protected computer	10.10.12.90	192.168.1.24

We recommend that you verify whether the DPM server is able to ping the protected computer’s backup network address (192.168.1.24). Similarly, the protected computer should be able to ping the DPM server’s backup network address (192.168.1.23).
At this stage, backup LAN configuration information is added to the DPM server as follows:

Add-BackupNetworkAddress -DpmServername DPM -Address 192.168.1.0/24 -SequenceNumber 1

Note
The “Address” parameter specifies the backup network/subnet.

The DPM agents on TestingServer and the protected server are restarted (“net stop dpmra” followed by “net start dpmra” on each server).
Finally, a backup task is triggered and the NIC used for backup data transfer verified using taskmgr->networking. The backup task must correspond to a data source on the protected server.

Note
Add-BackupNetworkAddress enables you to configure more than one backup network. You can also use the primary network as a fallback network while using the backup network. In the above example, the primary network could also have been added with SequenceNumber 2. As a result, if the primary network is removed and the name lookup of servers no longer returns 192.168.1.0/24 addresses, DPM can automatically start using the primary network for backup data traffic.

Note

Add-BackupNetworkAddress enables you to configure more than one backup network. You can also use the primary network as a fallback network while using the backup network. In the above example, the primary network could also have been added with SequenceNumber 2. As a result, if the primary network is removed and the name lookup of servers no longer returns 192.168.1.0/24 addresses, DPM can automatically start using the primary network for backup data traffic.