Oracle A423961 - Manual (Page 175)

Cause
Action
Cause
Action
Cause
Action
E – 31 Messages and Codes
ORA–06421: NETCMN: error detected in the read–in data
An error occurred in the recomputation of checksum or CRC. There is a possible
hardware failure in the communication nodes.
Contact your system administrator.
ORA–06422: NETCMN: error in sending data
SQL*Net was unable to transmit data to Oracle7 Server for Windows NT.
Attempt to reconnect to the Server. Contact your system administrator.
ORA–06423: NETCMN: error in receiving data
SQL*Net was unable to receive data from the Server.
Attempt to reconnect to the Server. Contact your system administrator.