给iptables规则添加注释，以此给你的老板和同事一个好印象。方法如下：
什么是iptables的注释呢？
iptables的注释一般使用在每条规则的后面，注释一般用 /* */ 包住。（具体的见下面的iptables规则中的注释 /* allow SSH to this host from anywhere */ ）
$ sudo iptables -L
Chain INPUT (policy DROP)
target prot opt source destination
ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED /* allow inbound traffic for established and related connections */
fail2ban-ssh tcp -- anywhere anywhere multiport dports ssh
ACCEPT tcp -- anywhere anywhere tcp dpt:ssh /* allow SSH to this host from anywhere */
ACCEPT udp -- anywhere anywhere udp dpt:route /* allow incoming RIP on the internal interface */
ACCEPT all -- localhost localhost /* allow any local-only traffic */
ACCEPT ipv6 -- tserv2.ash1.he.net anywhere /* allow IPv6 tunnel traffic from HE */
ACCEPT icmp -- anywhere anywhere /* allow ICMP traffic to this host from anywhere */</p>
<p> Chain FORWARD (policy DROP)
target prot opt source destination
ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED /* allow inbound traffic for established and related connections */
ACCEPT all -- anywhere anywhere /* allow all Internet bound traffic from the internal network */
ACCEPT icmp -- anywhere anywhere /* forward any ICMP traffic */</p>
<p> Chain OUTPUT (policy ACCEPT)
target prot opt source destination</p>
<p> Chain fail2ban-ssh (1 references)
target prot opt source destination
RETURN all -- anywhere anywhere
为新的iptables规则添加注释
为新的iptables规则添加注释的语法为 ： comment --comment “要添加的注释文字”
具体的例子：下面添加一条允许ssh流量通过的规则，并且给这条规则添加注释:
$ sudo iptables -A INPUT -p tcp -m tcp --dport 22 -m comment --comment "allow SSH to this host from anywhere" -j ACCEPT
然后用 -L 列出规则，就会看到刚才添加的规则和下面的一样：
$ sudo iptables -L</p>
<p>ACCEPT tcp -- anywhere anywhere tcp dpt:ssh /* allow SSH to this host from anywhere */
教程完！
