Preferred Network properties

Use the Preferred Network properties in the NetBackup Administration Console to specify to NetBackup which networks or interfaces to use for outgoing NetBackup traffic from the selected hosts. These properties apply to currently selected master servers, media servers, and clients.

The corresponding configuration option for this property is PREFERRED_NETWORK.

See PREFERRED_NETWORK option for NetBackup servers.

Note:

The Preferred Network setting in NetBackup does not apply to the Granular Recovery Technology (GRT) and VMware Instant Recovery features. Network settings that are configured in the operating system are used for these features during communication.

Preferred Network entries are not needed if NetBackup is configured using host names with IP addresses to which the operating system resolves and then routes correctly.

When external constraints prevent the environment from being corrected, Preferred Network entries may be useful as follows:

Can be used to prevent NetBackup from connecting to specific destination addresses.
Can be used to cause NetBackup to connect only to specific destination addresses.
Can be used to request a subset of local interfaces for source binding when making outbound connections.

Caution:

When used for source binding, the operating system may not honor the source binding list provided by NetBackup. If the operating system implements the weak host model, asymmetrical network routing may result. If asymmetrical routing occurs, the remote host may reject the inbound connection if it implements the strong host model. Similarly, stateful network devices may also drop asymmetrical connections. To ensure the use of specific outbound interfaces for specific remote hosts or networks, make sure that the OS name resolution and routing configurations are correct; create static host routes if needed. Ensure that all network drivers properly implement the IP and TCP networking protocols.

The local Preferred Network entries do not affect the forwarding profile that the local host returns to a remote host during initial CORBA connection setup; it will contain all the local plumbed interfaces. However, the End Point Selection algorithm within the remote process will utilize its local Preferred Network entries to evaluate the profile when selecting the destination for the subsequent CORBA connection.

With respect to source binding, the Preferred Network properties offer more flexibility than the Use specified network interface property in the Universal Settings properties. The Use specified network interface property can be used to specify only a single interface for NetBackup to use for outbound calls. The Preferred Network properties were introduced so that administrators can give more elaborate and constrictive instructions that apply to multiple individual networks, or a range of networks. For example, an administrator can configure a host to use any network except one. If both properties are specified, Use specified network interface overrides Preferred Network.

Note:

Do not inadvertently configure hosts so that they cannot communicate with any other host. Use the bptestnetconn utility to determine whether the hosts can communicate as you intend.

See bptestnetconn utility to display Preferred Network information.

Figure: Preferred Network dialog box

The Preferred Network dialog box contains a list of networks and the directive that has been configured for each.

Table: Preferred Network dialog box properties

Property	Description
List of network specifications for NetBackup communications	The list of preferred networks contains the following information: The Target column lists the networks (or host names or IP addresses) that have been given specific directives. If a network is not specifically listed as a target, or if a range of addresses does not include the target, NetBackup considers the target to be available for selection. Note that if the same network considerations apply for all of the hosts, the list of directives can be identical across all hosts in the NetBackup environment. If a directive contains an address that does not apply to a particular host, that host ignores it. For example, an IPv4-only host ignores IPv6 directives, and IPv6-only hosts ignore IPv4 directives. This lets the administrator use the same Preferred Network configurations for all the hosts in the NetBackup environment. The Specified as column indicates the directive for the network: Match, Prohibited, or Only. The Source column lists source binding information to use to filter addresses. The Source property is an optional configuration property.
Ordering arrows	Select a network in the list, then click the up or down arrow to change the order of the network in the list. The order can affect which network NetBackup selects. See Order of directive processing in the Preferred Network properties.
Add	Click Add to add a network to the Preferred Network properties. The directive for the network is configured in the Add Preferred Network Settings dialog box. See Table: Add or Change Preferred Network Settings dialog box properties.
Add to all	The Add to all button is active when multiple servers are selected.
Change	Select a network in the list, then click Change to change the Preferred Network properties. The directive is changed in the Change Preferred Network Settings dialog box. See Add or Change Preferred Network Settings dialog box.
Remove	Select a network in the list, then click Remove to remove the network from the list of preferred networks.

Preferred Network properties

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