Stefan informs us that its not possible to determine the interconnect IP Address from a database view in 9i RAC. He instead shows us how to use the oradebug command to find the IP Address. This is done with the oradebug ipc command and the tool writes a trace file containing the info needed. Stefan goes on to show us a complete example with how to find and read the trace file. Finding a trace file created by oradebug is done with the oradebug tracefile_name command.
I have links to two great papers about the oradebug on my oracle internals page