System Administration Guide: Network Interfaces and Network Virtualization

Types of IPMP Interface Configurations

An IPMP configuration typically consists of two or more physical interfaces on the same system that are attached to the same LAN. These interfaces can belong to an IPMP group in either of the following configurations:

A single interface can also be configured in its own IPMP group. The single interface IPMP group has the same behavior as an IPMP group with multiple interfaces. However, this IPMP configuration does not provide high availability for network traffic. If the underlying interface fails, then the system loses all capability to send or receive traffic. The purpose of configuring a single-interfaced IPMP group is to monitor the availability of the interface by using failure detection. By configuring a test address on the interface, you can set the daemon to track the interface by using probe-based failure detection. Typically, a single-interfaced IPMP group configuration is used in conjunction with other technologies that have broader failover capabilities, such as Sun Cluster software. The system can continue to monitor the status of the underlying interface. But the Sun Cluster software provides the functionalities to ensure availability of the network when failure occurs. For more information about the Sun Cluster software, see Sun Cluster Overview for Solaris OS.

An IPMP group without underlying interfaces can also exist, such as a group whose underlying interfaces have been removed. The IPMP group is not destroyed, but the group cannot be used to send and receive traffic. As underlying IP interfaces are brought online for the group, then the data addresses of the IPMP interface are allocated to these interfaces and the system resumes hosting network traffic.