linux配置端口映射

参考：http://blog.csdn.net/shilian_h/article/details/50475446

在使用非root用户启动tomcat时，如果tomcat配置为80端口，会报Permission denied错误，如：

 an 07, 2016 12:19:47 PM org.apache.coyote.AbstractProtocol init
 INFO: Initializing ProtocolHandler ["http-bio-80"]
 Jan 07, 2016 12:19:47 PM org.apache.coyote.AbstractProtocol init
 SEVERE: Failed to initialize end point associated with ProtocolHandler ["http-bio-80"
 ]
 java.net.BindException: Permission denied :80
     at org.apache.tomcat.util.net.JIoEndpoint.bind(JIoEndpoint.java:411)
     at org.apache.tomcat.util.net.AbstractEndpoint.init(AbstractEndpoint.java:640
 )
     at org.apache.coyote.AbstractProtocol.init(AbstractProtocol.java:434)
     at org.apache.coyote.http11.AbstractHttp11JsseProtocol.init(AbstractHttp11Jss
 eProtocol.java:119)
     at org.apache.catalina.connector.Connector.initInternal(Connector.java:978)
     at org.apache.catalina.util.LifecycleBase.init(LifecycleBase.java:102)
     at org.apache.catalina.core.StandardService.initInternal(StandardService.java
 :559)

在网上查询后，把tomcat改回8080端口，然后配置linux端口映射80到8080端口。

配置方式一、命令行方式。

（1）配置映射

 iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 8080

（2）保存配置。如果不保存，重启后此映射将失效

 service iptables save

配置方式二、修改 /etc/sysconfig/iptables文件，修改后要执行 service iptables restart重启防火墙。配置如：

 # Generated by iptables-save v1.4.7 on Thu Jan  7 12:37:28 2016
 *nat
 :PREROUTING ACCEPT [687:71239]
 :POSTROUTING ACCEPT [2:124]
 :OUTPUT ACCEPT [2:124]
 -A PREROUTING -p tcp -m tcp --dport 80 -j REDIRECT --to-ports 8080
 COMMIT
 # Completed on Thu Jan  7 12:37:28 2016
 # Generated by iptables-save v1.4.7 on Thu Jan  7 12:37:28 2016
 *filter
 :INPUT ACCEPT [0:0]
 :FORWARD ACCEPT [0:0]
 :OUTPUT ACCEPT [145:11884]
 -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
 -A INPUT -p icmp -j ACCEPT
 -A INPUT -i lo -j ACCEPT
 -A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT
 -A INPUT -p tcp -m state --state NEW -m tcp --dport 8080 -j ACCEPT
 -A INPUT -j REJECT --reject-with icmp-host-prohibited