In Oracle Solaris, a system with more than one interface is considered a multihomed host. The interfaces of a multihomed host connect to different subnets, either on different physical networks or on the same physical network. For step-by-step instructions on creating a multihomed host, see How to Create a Multihomed Host.
On a system with multiple interfaces that connect to the same subnet, you must configure the interfaces into an IPMP group first. Otherwise, the system cannot be a multihomed host. For more information about IPMP, see Chapter 2, About IPMP Administration, in Administering TCP/IP Networks, IPMP, and IP Tunnels in Oracle Solaris 11.2 .
A multihomed host does not forward IP packets, but you can configure a multihomed host to run routing protocols. You typically configure the following types of systems as multihomed hosts:
NFS servers, particularly those servers that function as large data centers, can be attached to more than one network to share files among a large pool of users. These servers do not need to maintain routing tables.
Database servers can have multiple network interfaces that provide resources to a large pool of users, just like NFS servers.
Firewall gateways are systems that provide the connection between a company's network and public networks such as the Internet. Administrators set up firewalls as a security measure. When configured as a firewall, the host does not pass packets between the networks that are attached to the host's interfaces. However, the host can still provide standard TCP/IP services such as ssh to authorized users.