TNS-12518: TNS:listener could not hand off client connection

OS: Red Hat Linux 2.6.9-34
Oracle 10gR2: 10.2.0.1.0

Error Message in listener.log:
TNS-12518: TNS:listener could not hand off client connection
TNS-12547: TNS:lost contact
TNS-12560: TNS:protocol adapter error
TNS-00517: Lost contact
Linux Error: 32: Broken pipe

Troubleshooting Steps:
1. check current listener connections and services
-bash-3.00$ lsnrctl ser

LSNRCTL for Linux: Version 10.2.0.1.0 - Production on 03-APR-2007 13:20:45
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC)))
Services Summary...
Service "mydb" has 1 instance(s).
Instance "mydb", status UNKNOWN, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:593 refused:23
LOCAL SERVER
Service "mydb" has 1 instance(s).
Instance "tedsdb", status READY, has 1 handler(s) for this service...
Handler(s):
"DEDICATED" established:572 refused:0 state:ready
LOCAL SERVER
The command completed successfully

2. check current listener.ora

3. take SID_LIST out of listener.ora as PMON can automatically register DB service with listener(since 8i).

3. set up local_listener in the instance

alter system set LOCAL_LISTENER="(address=(protocol=tcp)(host= mydbhost)(port=1521))" SCOPE=both;

4. restart listener.
lsnrctl stop
lsnrctl start

5. check listener service in a minute.

6. monitor listener connection usage.

7. turn on listener trace if cannot solve the problem.