On a server starting with the SPARC T7, SPARC M7, and SPARC S7 series server, the ILOM interconnect is used to communicate between the ldmd service and the SP.
Servers Starting With the SPARC T7, SPARC M7, and SPARC S7 Series Server: Check the ILOM interconnect state and re-enable the ilomconfig-interconnect service. See How to Verify the ILOM Interconnect Configuration and How to Re-Enable the ILOM Interconnect Service.
SPARC T4, SPARC T5, SPARC M5, and SPARC M6 Servers: Restart the ldmd service.
primary# svcadm enable ldmd
If these steps fail to restore communications, restart the SP.