Bug ID 6888928: If you use probe-based IPMP, the interfaces in the IPMP group might fail abruptly. This might happen shortly after you configure test addresses on the interfaces in the IPMP group for probe-based failure detection. The problem can occur with any network interface, virtual or physical, including Logical Domains virtual network devices.
Workaround: If you still want to use probe-based failure detection, install patch ID 142900-03. Or, you can disable probe-based failure detection by removing the test addresses, and use link-based failure detection. For more information, see IPMP Link-Based Only Failure Detection with Solaris 10 on SunSolve.
Starting with the Logical Domains 1.3 release, you can configure link-based IPMP for virtual network devices. See Using Link-Based IPMP in Logical Domains Virtual Networking in Logical Domains 1.3 Administration Guide.