Linux:iptables 常用命令
主機環境:
[root@test1280 ~]# cat /etc/redhat-release
CentOS release 6.8 (Final)
[root@test1280 ~]# uname -a
Linux test1280 2.6.32-642.el6.x86_64 #1 SMP Tue May 10 17:27:01 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
開放主機指定端口(以8080爲例):
方法一:修改配置文件(/etc/sysconfig/iptables)
修改前:
# Firewall configuration written by system-config-firewall
# Manual customization of this file is not recommended.
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
COMMIT
修改後:
# Firewall configuration written by system-config-firewall
# Manual customization of this file is not recommended.
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT
-A INPUT -m state --state NEW -m tcp -p tcp --dport 8080 -j ACCEPT
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
COMMIT
即:添加一行:
-A INPUT -m state --state NEW -m tcp -p tcp --dport 8080 -j ACCEPT
然後執行命令使進程重載配置生效:
[root@test1280 ~]# service iptables reload
iptables: Trying to reload firewall rules: [ OK ]
方法二:通過命令直接添加規則
執行命令:
[root@test1280 ~]# iptables -I INPUT -p tcp --dport 8080 -j ACCEPT
執行前狀態:
[root@test1280 ~]# service iptables status
Table: filter
Chain INPUT (policy ACCEPT)
num target prot opt source destination
1 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
2 ACCEPT icmp -- 0.0.0.0/0 0.0.0.0/0
3 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0
4 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:22
5 REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
Chain FORWARD (policy ACCEPT)
num target prot opt source destination
1 REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
Chain OUTPUT (policy ACCEPT)
num target prot opt source destination
執行後狀態:
[root@test1280 ~]# service iptables status
Table: filter
Chain INPUT (policy ACCEPT)
num target prot opt source destination
1 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:8080
2 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
3 ACCEPT icmp -- 0.0.0.0/0 0.0.0.0/0
4 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0
5 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:22
6 REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
Chain FORWARD (policy ACCEPT)
num target prot opt source destination
1 REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
Chain OUTPUT (policy ACCEPT)
num target prot opt source destination
可以看到新增一行:
1 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:8080
注意,以方法二新增的規則是存在於iptables進程內存中未持久化的。
如果需要持久化配置,需要執行:
[root@test1280 ~]# service iptables save
iptables: Saving firewall rules to /etc/sysconfig/iptables:[ OK ]
iptables是一個二進制可執行程序:
/sbin/iptables
[root@test1280 ~]# which iptables
/sbin/iptables
[root@test1280 ~]# file `which iptables`
/sbin/iptables: symbolic link to `/etc/alternatives/iptables.x86_64'
[root@test1280 ~]# file -L `which iptables`
/sbin/iptables: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.18, stripped
同時,有一個同名的shell腳本,也叫做iptables:
/etc/init.d/iptables
[root@test1280 ~]# file /etc/init.d/iptables
/etc/init.d/iptables: POSIX shell script text executable
1.查看狀態:service iptables status
[root@test1280 ~]# service iptables status
Table: filter
Chain INPUT (policy ACCEPT)
num target prot opt source destination
1 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
2 ACCEPT icmp -- 0.0.0.0/0 0.0.0.0/0
3 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0
4 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:22
5 REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
Chain FORWARD (policy ACCEPT)
num target prot opt source destination
1 REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
Chain OUTPUT (policy ACCEPT)
num target prot opt source destination
2.宕停服務:service iptables stop
[root@test1280 ~]# service iptables stop
iptables: Setting chains to policy ACCEPT: filter [ OK ]
iptables: Flushing firewall rules: [ OK ]
iptables: Unloading modules: [ OK ]
3.啓動服務:service iptables start
[root@test1280 ~]# service iptables start
iptables: Applying firewall rules: [ OK ]
3.重啓服務:service iptables restart
[root@test1280 ~]# service iptables restart
iptables: Setting chains to policy ACCEPT: filter [ OK ]
iptables: Flushing firewall rules: [ OK ]
iptables: Unloading modules: [ OK ]
iptables: Applying firewall rules: [ OK ]
4.重載配置:service iptables reload
[root@test1280 ~]# service iptables reload
iptables: Trying to reload firewall rules: [ OK ]
我們修改iptables配置文件 /etc/sysconfig/iptables 後,iptables 進程不會自動刷新配置。
此時,需要重啓(restart) iptables 或者 通知 iptables 動態重載(reload)配置。
5.保存配置:service iptables save
[root@test1280 ~]# service iptables save
iptables: Saving firewall rules to /etc/sysconfig/iptables:[ OK ]
我們通過 iptables 運行時修改的規則都是存在於進程內存空間,當我們重啓進程(服務),原先設置的配置將丟失。
如果要持久化 iptables 進程規則到配置文件,可以執行此命令。
通常,配置文件將被持久化到 /etc/sysconfig/iptables。
6.其他命令:
[root@test1280 ~]# service iptables
Usage: iptables {start|stop|reload|restart|condrestart|status|panic|save}
具體的實現可以查看 /etc/init.d/iptables 腳本。
在非root下查看iptables status,將會輸出:
[test1280@test1280 ~]$ service iptables status
iptables: Only usable by root. [WARNING]
參考:
1.https://www.cnblogs.com/pangguoming/p/5956151.html