问题描述：监听重启后稍等（大约一分钟后）检查监听状态，监听已经报错：
TNS-12541: TNS:no listener
TNS-12560: TNS:protocol adapter error
TNS-00511: No listener
Linux Error: 111: Connection refused
—–其实上面这种报错就是监听没启动–至于未启动的原因，可能是程序确实未启动或进程被KILL、挂起等各种原因总之是程序没启动。
检查日志发现有一条信息：
WARNING: Subscription for node down event still pending
搜索此条报错的信息，网上解答大致两种情况是：
情况一：Oracle 显示该问题为bug,并在10.2.0.3中已修复,但是在11.1.0.6中仍然存在。
情况二：监听无法在指定端口启动–可能前一次监听未正常退出或有其它程序占用了端口
但是回想此前监听程序一直运行正常，也查看了端口无异常。报着有错误先从自身查起的心态，回忆了最近对系统做过的所有变更。
从修改监听配置文件listener.ora、tnsnames.ora、动态监听的注册都检查了多遍。重建了多次监听均无法解决此故障。
终于想起了修改过/etc/hosts中的信息，于是重新修改此文件，将127.0.0.1条目恢复为系统默认的：127.0.0.1 localhost.localdomain localhost。重启监听正常
下面重现一下此错误的产生和解决。
#########################################################################################################################
实验思路说明： –一些无意义的输出就省略了未贴出。可以直接在文章左上的文章名下目录查看需要的小节。
实验一是正确配置/etc/hosts及监听正常运行的状态；
实验二模拟出错的场景为修改127.0.0.1 bys3.bys.com bys3，增加192.168.1.211 bys3.bys.com ，并分别修改listener.ora的三小步。
实验三模拟出错的场景为修改127.0.0.1 bys3.bys.com bys3，但是删除192.168.1.211 bys3.bys.com bys3条目。使用DBCA默认创建的listener.ora
#########################################################################################################################
实验一：将/etc/hosts中127.0.0.1条目设置为默认的：
127.0.0.1 localhost.localdomain localhost；192.168.1.211 bys3.bys.com bys3条目依然保留。
重新启动监听可以正常。
[root@bys3 ~]# cat /etc/hosts
127.0.0.1 localhost.localdomain localhost
::1 localhost6.localdomain6 localhost6
192.168.1.211 bys3.bys.com bys3
[root@bys3 ~]# ping bys3
PING bys3.bys.com (192.168.1.211) 56(84) bytes of data.
64 bytes from bys3.bys.com (192.168.1.211): icmp_seq=1 ttl=64 time=0.232 ms
^C
--- bys3.bys.com ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.232/0.232/0.232/0.000 ms
[root@bys3 ~]# ping bys3.bys.com
PING bys3.bys.com (192.168.1.211) 56(84) bytes of data.
64 bytes from bys3.bys.com (192.168.1.211): icmp_seq=1 ttl=64 time=0.125 ms
^C
[oracle@bys3 admin]$ cat listener.ora
# listener.ora Network Configuration File: /u01/app/oracle/product/11.2.0/dbhome_1/network/admin/listener.ora
# Generated by Oracle configuration tools.
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = bys3.bys.com)(PORT = 1521))
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
)
)
ADR_BASE_LISTENER = /u01
[oracle@bys3 admin]$
lsnrctl start
LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 18-NOV-2013 10:56:55
Copyright (c) 1991, 2013, Oracle. All rights reserved.
Starting /u01/app/oracle/product/11.2.0/dbhome_1/bin/tnslsnr: please wait...
TNSLSNR for Linux: Version 11.2.0.4.0 - Production
System parameter file is /u01/app/oracle/product/11.2.0/dbhome_1/network/admin/listener.ora
Log messages written to /u01/diag/tnslsnr/bys3/listener/alert/log.xml
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=bys3.bys.com)(PORT=1521)))
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=bys3.bys.com)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.4.0 - Production
Start Date 18-NOV-2013 10:56:57
Uptime 0 days 0 hr. 0 min. 0 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/oracle/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File /u01/diag/tnslsnr/bys3/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=bys3.bys.com)(PORT=1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
The listener supports no services
The command completed successfully
[oracle@bys3 admin]$
lsnrctl status --监听已经正常运行，实例已经注册进来了。--动态注册
LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 18-NOV-2013 10:59:10
Copyright (c) 1991, 2013, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=bys3.bys.com)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.4.0 - Production
Start Date 18-NOV-2013 10:56:57
Uptime 0 days 0 hr. 2 min. 12 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/oracle/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File /u01/diag/tnslsnr/bys3/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=bys3.bys.com)(PORT=1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
Services Summary...
Service "bys3" has 1 instance(s).
Instance "bys3", status READY, has 1 handler(s) for this service...
The command completed successfully###############################################################################################################
实验二：修改/etc/hosts中127.0.0.1条目，并分别修改listener.ora的三小步
将127.0.0.1 localhost.localdomain localhost条目改为127.0.0.1 bys3.bys.com bys3后，
再增加一条IP与域名对应即：192.168.1.211 bys3.bys.com
如下：
[root@bys3 ~]# cat /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
#127.0.0.1 localhost.localdomain localhost
127.0.0.1 bys3.bys.com bys3
::1 localhost6.localdomain6 localhost6
192.168.1.211 bys3.bys.com bys3
[root@bys3 ~]# ping bys3
PING bys3.bys.com (127.0.0.1) 56(84) bytes of data.
64 bytes from bys3.bys.com (127.0.0.1): icmp_seq=1 ttl=64 time=0.122 ms
[root@bys3 ~]# ping bys3.bys.com
PING bys3.bys.com (127.0.0.1) 56(84) bytes of data.
64 bytes from bys3.bys.com (127.0.0.1): icmp_seq=1 ttl=64 time=0.118 ms
在修改了/etc/hosts中127.0.0.1条目后，分别实验了以下三种情况（均为修改listener.ora文件），
监听日志中的报错信息均为：WARNING: Subscription for node down event still pending
监听配置一：使用NETCA创建监听时的默认listener.ora文件
此时重启监听，然后稍等（大约一分钟后）检查监听状态，监听已经报错，监听日志中报错为WARNING: Subscription for node down event still pending
监听配置文件：
[oracle@bys3 admin]$ cat listener.ora
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = bys3.bys.com)(PORT = 1521))
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
)
)
ADR_BASE_LISTENER = /u01
启动监听并查看状态--查看状态要在监听启动后稍等一下查看，会报错。刚启动完成时还是正常的。
[oracle@bys3 admin]$ lsnrctl start ---启动监听
LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 18-NOV-2013 10:26:44
Copyright (c) 1991, 2013, Oracle. All rights reserved.
Starting /u01/app/oracle/product/11.2.0/dbhome_1/bin/tnslsnr: please wait...
TNSLSNR for Linux: Version 11.2.0.4.0 - Production
System parameter file is /u01/app/oracle/product/11.2.0/dbhome_1/network/admin/listener.ora
Log messages written to /u01/diag/tnslsnr/bys3/listener/alert/log.xml
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=bys3.bys.com)(PORT=1521)))
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=bys3.bys.com)(PORT=1521)))
STATUS of the LISTENER
------------------------
Alias LISTENER
Version TNSLSNR for Linux: Version 11.2.0.4.0 - Production
Start Date 18-NOV-2013 10:26:45
Uptime 0 days 0 hr. 0 min. 0 sec
Trace Level off
Security ON: Local OS Authentication
SNMP OFF
Listener Parameter File /u01/app/oracle/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File /u01/diag/tnslsnr/bys3/listener/alert/log.xml
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=bys3.bys.com)(PORT=1521)))
(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
The listener supports no services
The command completed successfully
[oracle@bys3 admin]$
lsnrctl status ---监听启动后，稍等一下，查看状态，监听程序已经挂了。
LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 18-NOV-2013 10:27:09
Copyright (c) 1991, 2013, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=bys3.bys.com)(PORT=1521)))
TNS-12541: TNS:no listener
TNS-12560: TNS:protocol adapter error
TNS-00511: No listener
Linux Error: 111: Connection refused
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
TNS-12541: TNS:no listener
TNS-12560: TNS:protocol adapter error
TNS-00511: No listener
Linux Error: 111: Connection refused############################################################################################
监听配置二：把默认监听配置文件中(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))这一行删除
此时重启监听，然后稍等（大约一分钟后）检查监听状态，监听已经报错，监听日志中报错为WARNING: Subscription for node down event still pending
监听配置文件：
[oracle@bys3 admin]$ cat listener.ora
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = bys3.bys.com)(PORT = 1521))
)
)
ADR_BASE_LISTENER = /u01
[oracle@bys3 admin]$ lsnrctl start
---启动监听--输出信息和上一步监听配置一中一样，不太重要的信息就不贴了。
LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 18-NOV-2013 10:37:24
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=bys3.bys.com)(PORT=1521)))
The listener supports no services
The command completed successfully
[oracle@bys3 admin]$ lsnrctl status ---监听启动后，稍等一下，查看状态，监听程序已经挂了。
LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 18-NOV-2013 10:39:12
Copyright (c) 1991, 2013, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=bys3.bys.com)(PORT=1521)))
TNS-12541: TNS:no listener
TNS-12560: TNS:protocol adapter error
TNS-00511: No listener
Linux Error: 111: Connection refused############################################################################################
监听配置三：把默认监听配置文件中(ADDRESS = (PROTOCOL = TCP)(HOST = bys3.bys.com)(PORT = 1521))这一行的HOST中的域名改为IP
此时重启监听，然后稍等（大约一分钟后）检查监听状态，监听已经报错，监听日志中报错为WARNING: Subscription for node down event still pending
监听配置文件：
############################################################################################
[oracle@bys3 admin]$ cat listener.ora
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.211)(PORT = 1521))
)
)
ADR_BASE_LISTENER = /u01
[oracle@bys3 admin]$ ping 192.168.1.211
PING 192.168.1.211 (192.168.1.211) 56(84) bytes of data.
64 bytes from 192.168.1.211: icmp_seq=1 ttl=64 time=1.04 ms
[oracle@bys3 admin]
$ lsnrctl start
---启动监听--输出信息和监听配置一中一样，不太重要的信息就不贴了。
Listening Endpoints Summary...
(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.168.1.211)(PORT=1521)))
The listener supports no services
The command completed successfully
[oracle@bys3 admin]$
lsnrctl status ---监听启动后，稍等一下，查看状态，监听程序已经挂了。
LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 18-NOV-2013 10:42:27
Copyright (c) 1991, 2013, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.1.211)(PORT=1521)))
TNS-12541: TNS:no listener
TNS-12560: TNS:protocol adapter error
TNS-00511: No listener
Linux Error: 111: Connection refused实验三：模拟出错的场景为修改127.0.0.1 bys3.bys.com bys3，但是删除192.168.1.211 bys3.bys.com bys3条目。使用DBCA默认创建的listener.ora
此时重启监听，然后稍等（大约一分钟后）检查监听状态，监听已经报错，监听日志中报错为WARNING: Subscription for node down event still pending
监听配置文件：
[root@bys3 ~]# cat /etc/hosts
# Do not remove the following line, or various programs
# that require network functionality will fail.
#127.0.0.1 localhost.localdomain localhost
::1 localhost6.localdomain6 localhost6
#192.168.1.211 bys3.bys.com bys3
127.0.0.1 bys3.bys.com bys3
[root@bys3 ~]# ping bys3.bys.com
PING bys3.bys.com (127.0.0.1) 56(84) bytes of data.
64 bytes from bys3.bys.com (127.0.0.1): icmp_seq=1 ttl=64 time=0.305 ms
^C
[root@bys3 ~]# ping bys3
PING bys3.bys.com (127.0.0.1) 56(84) bytes of data.
64 bytes from bys3.bys.com (127.0.0.1): icmp_seq=1 ttl=64 time=0.114 ms
^C
[oracle@bys3 admin]$ cat listener.ora
# listener.ora Network Configuration File: /u01/app/oracle/product/11.2.0/dbhome_1/network/admin/listener.ora
# Generated by Oracle configuration tools.
LISTENER =
(DESCRIPTION_LIST =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = bys3.bys.com)(PORT = 1521))
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
)
)
ADR_BASE_LISTENER = /u01
[oracle@bys3 admin]$
lsnrctl start
---启动监听--输出信息和上一步监听配置一中一样，不太重要的信息就不贴了。
The listener supports no services
The command completed successfully
[oracle@bys3 admin]$
lsnrctl status
--监听启动后，稍等一下，查看状态，监听程序已经挂了。
LSNRCTL for Linux: Version 11.2.0.4.0 - Production on 18-NOV-2013 11:13:48
Copyright (c) 1991, 2013, Oracle. All rights reserved.
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=bys3.bys.com)(PORT=1521)))
TNS-12541: TNS:no listener
TNS-12560: TNS:protocol adapter error
TNS-00511: No listener
Linux Error: 111: Connection refused
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
TNS-12541: TNS:no listener
TNS-12560: TNS:protocol adapter error
TNS-00511: No listener
Linux Error: 111: Connection refused服务器托管，北京服务器托管，服务器租用 http://www.fwqtg.net
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