I 顯示INPUT規則
# iptables -L INPUT -n --line-numbers
Chain INPUT (policy ACCEPT)
num target prot opt source destination
1 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 ctstate RELATED,ESTABLISHED
2 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0
3 INPUT_direct all -- 0.0.0.0/0 0.0.0.0/0
4 INPUT_ZONES_SOURCE all -- 0.0.0.0/0 0.0.0.0/0
5 INPUT_ZONES all -- 0.0.0.0/0 0.0.0.0/0
6 ACCEPT icmp -- 0.0.0.0/0 0.0.0.0/0
7 REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
II 添加允許21端口進行tcp方式訪問
# iptables -I INPUT 6 -p tcp --dport 21 -j ACCEPT
或則增加新規則
# iptables -A INPUT -m state --state NEW -p tcp --dport 21 -j ACCEPT
III 保存和恢復
# service iptables save
# service iptables restart
IV 再次顯示INPUT規則
# iptables -L INPUT -n --line-numbers
Chain INPUT (policy ACCEPT)
num target prot opt source destination
1 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0 ctstate RELATED,ESTABLISHED
2 ACCEPT all -- 0.0.0.0/0 0.0.0.0/0
3 INPUT_direct all -- 0.0.0.0/0 0.0.0.0/0
4 INPUT_ZONES_SOURCE all -- 0.0.0.0/0 0.0.0.0/0
5 INPUT_ZONES all -- 0.0.0.0/0 0.0.0.0/0
6 ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:21
7 ACCEPT icmp -- 0.0.0.0/0 0.0.0.0/0
8 REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-host-prohibited
V 完成
參考:http://www.csdn.net/article/2012-01-17/310905