[root@v01-svn-test-server online]# iptables -F#清空规则
[root@v01-svn-test-server online]# iptables -L#
Chain INPUT (policy ACCEPT)
target prot opt source destination Chain FORWARD (policy ACCEPT)
target prot opt source destination Chain OUTPUT (policy ACCEPT)
target prot opt source destination
[root@v01-svn-test-server online]# iptables -A INPUT -p tcp --dport 22 -j ACCEPT /*允许包从22端口进入*/
[root@v01-svn-test-server online]# cat /etc/sysconfig/iptables
# 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
[root@v01-svn-test-server online]# iptables -A OUTPUT -p tcp --sport 22 -m state --state ESTABLISHED -j ACCEPT #允许从22端口进入的包返回
[root@v01-svn-test-server online]# iptables -A INPUT -s 127.0.0.1 -d 127.0.0.1 -j ACCEPT #允许本机访问本机
[root@v01-svn-test-server online]# iptables -A OUTPUT -s 127.0.0.1 -j ACCEPT
[root@v01-svn-test-server online]# iptables -A INPUT -p tcp -s 0/0 --dport 80 -j ACCEPT #允许所以IP访问80端 口
[root@v01-svn-test-server online]# iptables -A OUTPUT -p tcp --sport 80 -m state --state ESTABLISHED -j ACCEPT
service iptables save
来实现保存到配置文件。
这样重启计算机后,CentOS防火墙默认已经开放了80和22端口。
[root@v01-svn-test-server online]# service iptables save#保存配置
iptables: Saving firewall rules to /etc/sysconfig/iptables:[ OK ]
[root@v01-svn-test-server online]# iptables -L
Chain INPUT (policy ACCEPT)
target prot opt source destination
ACCEPT tcp -- anywhere anywhere tcp dpt:ssh
ACCEPT all -- localhost localhost
ACCEPT tcp -- anywhere anywhere tcp dpt:http Chain FORWARD (policy ACCEPT)
target prot opt source destination Chain OUTPUT (policy ACCEPT)
target prot opt source destination
ACCEPT tcp -- anywhere anywhere tcp spt:ssh state ESTABLISHED
ACCEPT all -- localhost anywhere
ACCEPT tcp -- anywhere anywhere tcp spt:http state ESTABLISHED
[root@v01-svn-test-server online]# cat /etc/sysconfig/iptables
# Generated by iptables-save v1.4.7 on Wed Jun 1 20:55:03 2016
*filter
:INPUT ACCEPT [50:5062]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -p tcp -m tcp --dport 22 -j ACCEPT
-A INPUT -s 127.0.0.1/32 -d 127.0.0.1/32 -j ACCEPT
-A INPUT -p tcp -m tcp --dport 80 -j ACCEPT
-A OUTPUT -p tcp -m tcp --sport 22 -m state --state ESTABLISHED -j ACCEPT
-A OUTPUT -s 127.0.0.1/32 -j ACCEPT
-A OUTPUT -p tcp -m tcp --sport 80 -m state --state ESTABLISHED -j ACCEPT
COMMIT
# Completed on Wed Jun 1 20:55:03 2016
查看防火墙信息：
[root@v01-svn-test-server online]# 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:22
2 ACCEPT all -- 127.0.0.1 127.0.0.1
3 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:80 Chain FORWARD (policy ACCEPT)
num target prot opt source destination Chain OUTPUT (policy ACCEPT)
num target prot opt source destination
1 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp spt:22 state ESTABLISHED
2 ACCEPT all -- 127.0.0.1 0.0.0.0/0
3 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp spt:80 state ESTABLISHED