研发说无法访问数据库，数据库正常运行，那就可能是监听有问题，
一波简单操作搞定。

[oracle@entegor-1 ~]$ lsnrctl start

LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 17-AUG-2018 09:04:01

Copyright (c) 1991, 2013, Oracle.  All rights reserved.

Starting /oracle/app/oracle/11.2.0/db_1/bin/tnslsnr: please wait...

TNSLSNR for Linux: Version 11.2.0.4.0 - Production
Log messages written to /oracle/app/oracle/diag/tnslsnr/entegor-1/listener/alert/log.xml
Error listening on: (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
TNS-12542: TNS:address already in use
 TNS-12560: TNS:protocol adapter error
  TNS-00512: Address already in use
   Linux Error: 98: Address already in use

Listener failed to start. See the error message(s) above...

[root@entegor-1 ~]# su - grid
[grid@entegor-1 ~]$ lsnrctl status

LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 17-AUG-2018 09:03:32

Copyright (c) 1991, 2013, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=LISTENER)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 11.2.0.4.0 - Production
Start Date                31-JAN-2018 11:17:57
Uptime                    197 days 21 hr. 45 min. 34 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File   /oracle/app/11.2.0/grid/network/admin/listener.ora
Listener Log File         /oracle/app/grid/diag/tnslsnr/entegor-1/listener/alert/log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=LISTENER)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=6.1.14.125)(PORT=1521)))
Services Summary...
Service "+ASM" has 1 instance(s).
  Instance "+ASM1", status READY, has 1 handler(s) for this service...
The command completed successfully

[grid@entegor-1 ~]$ lsnrctl stop

LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 17-AUG-2018 09:04:16

Copyright (c) 1991, 2013, Oracle.  All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=LISTENER)))
The command completed successfully
[grid@entegor-1 ~]$ exit
logout
[root@entegor-1 ~]# su - oracle
[oracle@entegor-1 ~]$ lsnrctl start

LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 17-AUG-2018 09:04:25

Copyright (c) 1991, 2013, Oracle.  All rights reserved.

Starting /oracle/app/oracle/11.2.0/db_1/bin/tnslsnr: please wait...

TNSLSNR for Linux: Version 11.2.0.4.0 - Production
Log messages written to /oracle/app/oracle/diag/tnslsnr/entegor-1/listener/alert/log.xml
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=entegor-1)(PORT=1521)))

Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 11.2.0.4.0 - Production
Start Date                17-AUG-2018 09:04:25
Uptime                    0 days 0 hr. 0 min. 1 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Log File         /oracle/app/oracle/diag/tnslsnr/entegor-1/listener/alert/log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=entegor-1)(PORT=1521)))
The listener supports no services
The command completed successfully

[oracle@entegor-1 ~]$ lsnrctl status

LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 17-AUG-2018 09:14:12

Copyright (c) 1991, 2013, Oracle.  All rights reserved.

Connecting to (ADDRESS=(PROTOCOL=tcp)(HOST=)(PORT=1521))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version                   TNSLSNR for Linux: Version 11.2.0.4.0 - Production
Start Date                17-AUG-2018 09:04:25
Uptime                    0 days 0 hr. 9 min. 46 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Log File         /oracle/app/oracle/diag/tnslsnr/entegor-1/listener/alert/log.xml
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=entegor-1)(PORT=1521)))
Services Summary...
Service "+ASM" has 1 instance(s).
  Instance "+ASM1", status READY, has 1 handler(s) for this service...
Service "entegor" has 1 instance(s).
  Instance "entegor1", status READY, has 2 handler(s) for this service...
Service "entegorXDB" has 1 instance(s).
  Instance "entegor1", status READY, has 1 handler(s) for this service...
The command completed successfully
[oracle@entegor-1 ~]$