Cause: Unable to establish
connection.
Action: Use diagnostic procedures to
ascertain exact problem.

Relared Errors:
ORA-06416:
NETCMN: error on test
ORA-06419:
NETCMN: server can not start oracle
ORA-06420:
NETCMN: SID lookup failure
ORA-06421:
NETCMN: Error detected in the read-in data
ORA-06422:
NETCMN: Error in sending data
ORA-06423:
NETCMN: Error in receiving data
ORA-06430:
ssaio: Seals do not match
ORA-06431:
ssaio: Invalid Block number
ORA-06432:
ssaio: Buffer Not Aligned
ORA-06433:
ssaio: LSEEK error, unable to seek to requested block.