White Papers

Technical support and resources
Document 339
2 Configuration using the TUI
The Text User Interface (TUI) is used for configuring OpenManage Enterprise. Access it through the
hypervisor console. Two new items have been added to the main menu for multihoming: Select Primary
Network Interface and Configure Static Routes.
Accessing the TUI
2.1 Select a Primary Network Interface
The primary interface is expected to be the public facing interface that allows for corporate network and
Internet connectivity. Primary interface selection also gives priority to the selected interface in terms of
routing. In other words, the primary interface owns the default route and has routing priority in the event of
ambiguity. Different firewall rules are applied to the primary interface as well, which allow for tighter access
control such as UI access restriction by IP range. The secondary interface has full access to the appliance but
may require a static route be defined for connectivity.
2.2 Routing
An appliance with a single network interface has no need for static routes, since the only interface owns the
default route. All requests for which a specific route cannot be determined are sent on the default route. For
example, consider an appliance with an IP address of 100.10.10.70/24 and a gateway address of
100.10.10.1. If a request is made to a system on another network, 110.11.11.8 for instance, the system
consults its routing table and attempt to derive the appropriate route. If no route is found, it uses the default
route and the request is forwarded to the gateway at 100.10.10.1.
When a second network interface is added, the primary interface will own the default route. Expanding on the
example above, assume the appliance has a secondary interface with an IP address of 173.10.1.33 on
subnet 173.10.1.0/24. To discover and manage a system on subnet 173.10.3.0/24 that is only routable on the
secondary network, a static route must be provided. In this case, the static route 173.10.3.0/24 to 173.10.1.1
is added, directing traffic for 173.10.3.0/24 to the router at 173.10.1.1. Without this additional route, the
appliance would direct network traffic intended for this subnet to the default route, and systems on the
173.10.3.0/24 network would be unreachable. This example is illustrated below.