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 ~]$