Linux iptables命令详解程序员

iptables命令主要是设置防火墙信息的

常见命令参数

Usage: iptables -[AD] chain rule-specification [options] 
       iptables -I chain [rulenum] rule-specification [options] 
       iptables -R chain rulenum rule-specification [options] 
       iptables -D chain rulenum [options] 
       iptables -[LS] [chain [rulenum]] [options] 
       iptables -[FZ] [chain] [options] 
       iptables -[NX] chain 
       iptables -E old-chain-name new-chain-name 
       iptables -P chain target [options] 
       iptables -h (print this help information) 
 
Commands: 
Either long or short options are allowed. 
  --append  -A chain            Append to chain 
  --delete  -D chain            Delete matching rule from chain 
  --delete  -D chain rulenum 
                                Delete rule rulenum (1 = first) from chain 
  --insert  -I chain [rulenum] 
                                Insert in chain as rulenum (default 1=first) 
  --replace -R chain rulenum 
                                Replace rule rulenum (1 = first) in chain 
  --list    -L [chain [rulenum]] 
                                List the rules in a chain or all chains 
  --list-rules -S [chain [rulenum]] 
                                Print the rules in a chain or all chains 
  --flush   -F [chain]          Delete all rules in  chain or all chains 
  --zero    -Z [chain [rulenum]] 
                                Zero counters in chain or all chains 
  --new     -N chain            Create a new user-defined chain 
  --delete-chain 
            -X [chain]          Delete a user-defined chain 
  --policy  -P chain target 
                                Change policy on chain to target 
  --rename-chain 
            -E old-chain new-chain 
                                Change chain name, (moving any references)

常见命令展示

1、查看

iptables -nL --line-number 
 
-L 查看当前表的所有规则，默认查看的是filter表，如果要查看NAT表，加上-t NAT参数 
-n 不对ip地址进行反查，加上这个参数显示速度会快很多 
-v 输出详细信息，包含通过该规则的数据包数量，总字节数及相应的网络接口 
–line-number 显示规则的序列号，这个参数在删除或修改规则时会用到

2、添加

添加规则有两个参数：-A和-I。其中-A是添加到规则的末尾；-I可以插入到指定位置，没有指定位置的话默认插入到规则的首部。  

# 2.1添加一条规则到尾部： 
iptables -A INPUT -s 192.168.1.5 -j DROP 
# 2.2插入一条规则到第三行，将行数直接写到规则链的后面 
iptables -I INPUT 3 -s 192.168.1.3 -j DROP

3、删除

# 删除第二行规则 iptables -D INPUT 2

4、修改

# 修改用-R参数 
iptables -R INPUT 3 -j ACCEPT