How IP Addresses Apply to Network Interfaces

To connect to the network, a system must have at least one physical network interface. Each network interface must have its own unique IP address. During Solaris installation, you must supply the IP address for the first interface that the installation program finds. Usually that interface has the name device-name0, for example eri0 or hme0. This interface is considered the primary network interface.

If you add a second network interface to a host, that interface also must have its own unique IP address. When you add the second network interface, the host then becomes multihomed. By contrast, when you add a second network interface to a host and enable IP forwarding, that host becomes a router. See Configuring an IPv4 Router for an explanation.

Each network interface has a device name, a device driver, and an associated device file in the /devices directory. The network interface might have a device name such as eri or smc0, which are device names for two commonly used Ethernet interfaces.

For information and tasks related to interfaces, refer to Part I, Administering Single Interfaces, in System Administration Guide: Network Interfaces and Network Virtualization.

This book assumes that your systems have Ethernet network interfaces. If you plan to use different network media, refer to the manuals that come with the network interface for configuration information.