ORA-12170：TNS：连接超时

转载自：http://www.cnblogs.com/kerrycode/archive/2012/12/14/2818421.html

在Red Hat Enterprise Linux Server Releae 5.5 成功安装ORACLE 10g 后，在客户端配置TNS后，测试是否可以连接到数据块服务器，结果报错： ORA-12170：TNS：连接超时

1：首先检查网络是否能ping通，如下所示，网络是畅通的。

2：检查TNS配置（TNS配置也没有问题）

GSP =(DESCRIPTION =(ADDRESS =(PROTOCOL = TCP)(HOST = 172.20.36.79)(PORT = 1521))(CONNECT_DATA=(SERVER = DEDICATED)(SERVICE_NAME = gsp)))

3：查看服务器监听服务是否启动

[oracle@wgods ~]$ lsnrctl statusLSNRCTL for Linux: Version 10.2.0.1.0 - Production on 14-DEC-2012 15:51:13Copyright (c) 1991, 2005, Oracle. All rights reserved.Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1)))STATUS of the LISTENER------------------------Alias LISTENERVersion TNSLSNR for Linux: Version 10.2.0.1.0 - ProductionStart Date 14-DEC-2012 13:15:28Uptime 0 days 2 hr. 35 min. 45 secTrace Level offSecurity ON: Local OS AuthenticationSNMP OFFListener Parameter File /database/oracle/product/dbhome/network/admin/listener.oraListener Log File /database/oracle/product/dbhome/network/log/listener.logListening Endpoints Summary...(DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1)))(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=wgods)(PORT=1521)))Services Summary...Service "PLSExtProc" has 1 instance(s).Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...Service "gsp" has 2 instance(s).Instance "gsp", status UNKNOWN, has 1 handler(s) for this service...Instance "gsp", status READY, has 1 handler(s) for this service...Service "gspXDB" has 1 instance(s).Instance "gsp", status READY, has 1 handler(s) for this service...Service "gsp_XPT" has 1 instance(s).Instance "gsp", status READY, has 1 handler(s) for this service...The command completed successfully

4：使用tnsping命令检查，报TNS-12535: TNS: 操作超时，这时我们可以肯定是防火墙的问题了。

C:\Users\kerry>tnsping 172.20.32.79TNS Ping Utility for 32-bit Windows: Version 11.2.0.1.0 - Production on 14-12月-2012 15:47:15Copyright (c) 1997, 2010, Oracle. All rights reserved.已使用的参数文件:E:\app\kerry\product\11.2.0\dbhome_1\network\admin\sqlnet.ora已使用 EZCONNECT 适配器来解析别名尝试连接 (DESCRIPTION=(CONNECT_DATA=(SERVICE_NAME=))(ADDRESS=(PROTOCOL=TCP)(HOST=172.20.32.79)(PORT=1521)))TNS-12535: TNS: 操作超时

对于防火墙问题，我们可以有两种解决方案：

1：关闭防火墙（这种方案不怎么好，关闭防火墙，会带来许多安全隐患）

[root@wgods ~]# service iptables stopFlushing firewall rules: [ OK ]Setting chains to policy ACCEPT: filter [ OK ]Unloading iptables modules: [ OK ]

2：修改iptables，开放1521端口，允许1521端口被连接

2.1编辑iptables文件：
直接改iptables配置就可以了：vim /etc/sysconfig/iptables。
添加-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport 1521 -j ACCEPT记录。

[root@wgods sysconfig]# vi iptables# Generated by iptables-save v1.3.5 on Fri Dec 14 17:03:58 2012*filter:INPUT ACCEPT [0:0]:FORWARD ACCEPT [0:0]:OUTPUT ACCEPT [1749:243629]:RH-Firewall-1-INPUT - [0:0]-A INPUT -j RH-Firewall-1-INPUT-A FORWARD -j RH-Firewall-1-INPUT-A RH-Firewall-1-INPUT -i lo -j ACCEPT-A RH-Firewall-1-INPUT -p icmp -m icmp --icmp-type any -j ACCEPT-A RH-Firewall-1-INPUT -p esp -j ACCEPT-A RH-Firewall-1-INPUT -p ah -j ACCEPT-A RH-Firewall-1-INPUT -d 224.0.0.251 -p udp -m udp --dport 5353 -j ACCEPT-A RH-Firewall-1-INPUT -p udp -m udp --dport 631 -j ACCEPT-A RH-Firewall-1-INPUT -p tcp -m tcp --dport 631 -j ACCEPT-A RH-Firewall-1-INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport 21 -j ACCEPT-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport 25 -j ACCEPT-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport 23 -j ACCEPT-A RH-Firewall-1-INPUT -p tcp -m state --state NEW -m tcp --dport 1521 -j ACCEPT -A RH-Firewall-1-INPUT -j REJECT --reject-with icmp-host-prohibitedCOMMIT# Completed on Fri Dec 14 17:03:58 2012~~~~~"iptables" 24L, 1212C written

2.2 重启iptables服务

[root@wgods sysconfig]# service iptables restartFlushing firewall rules: [ OK ]Setting chains to policy ACCEPT: filter [ OK ]Unloading iptables modules: [ OK ]Applying iptables firewall rules: [ OK ]Loading additional iptables modules: ip_conntrack_netbios_ns ip_conntrack_ftp [ OK ]

2.3 保存新增的规则，以免下次重启机器后，配置规则失效

[root@wgods sysconfig]# service iptables saveSaving firewall rules to /etc/sysconfig/iptables: [ OK ]

2.4 查看1521端口是否开放，允许连接（见红色部分）

[root@wgods sysconfig]# iptables -L -n
Chain INPUT (policy ACCEPT)
target prot opt source destination
RH-Firewall-1-INPUT all – 0.0.0.0/0 0.0.0.0/0

Chain FORWARD (policy ACCEPT)
target prot opt source destination
RH-Firewall-1-INPUT all – 0.0.0.0/0 0.0.0.0/0

Chain OUTPUT (policy ACCEPT)
target prot opt source destination

Chain RH-Firewall-1-INPUT (2 references)
target prot opt source destination
ACCEPT all – 0.0.0.0/0 0.0.0.0/0
ACCEPT icmp – 0.0.0.0/0 0.0.0.0/0 icmp type 255
ACCEPT esp – 0.0.0.0/0 0.0.0.0/0
ACCEPT ah – 0.0.0.0/0 0.0.0.0/0
ACCEPT udp – 0.0.0.0/0 224.0.0.251 udp dpt:5353
ACCEPT udp – 0.0.0.0/0 0.0.0.0/0 udp dpt:631
ACCEPT tcp – 0.0.0.0/0 0.0.0.0/0 tcp dpt:631
ACCEPT all – 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
ACCEPT tcp – 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:21
ACCEPT tcp – 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:25
ACCEPT tcp – 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:22
ACCEPT tcp – 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:23
ACCEPT tcp – 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:1521
REJECT all – 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
[root@wgods sysconfig]#

从客户端用PL/SQL Developer连接数据库，问题解决。