参考官方文档：https://wiki.debian.org/iptables

先查看当前规则：iptables -L

默认规则如下时表示当前规则为空

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


创建一个iptables规则文件并写入:

nano /etc/iptables.test.rules
写入：


*filter

# Allows all loopback (lo0) traffic and drop all traffic to 127/8 that doesn't use lo0
-A INPUT -i lo -j ACCEPT
-A INPUT ! -i lo -d 127.0.0.0/8 -j REJECT

# Accepts all established inbound connections
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT

# Allows all outbound traffic
# You could modify this to only allow certain traffic
-A OUTPUT -j ACCEPT

# Allows HTTP and HTTPS connections from anywhere (the normal ports for websites)
-A INPUT -p tcp --dport 80 -j ACCEPT
-A INPUT -p tcp --dport 443 -j ACCEPT

# Allows SSH connections 
# The --dport number is the same as in /etc/ssh/sshd_config
-A INPUT -p tcp -m state --state NEW --dport 22 -j ACCEPT

# Now you should read up on iptables rules and consider whether ssh access 
# for everyone is really desired. Most likely you will only allow access from certain IPs.

# Allow ping
#  note that blocking other types of icmp packets is considered a bad idea by some
#  remove -m icmp --icmp-type 8 from this line to allow all kinds of icmp:
#  https://security.stackexchange.com/questions/22711
-A INPUT -p icmp -m icmp --icmp-type 8 -j ACCEPT

# log iptables denied calls (access via 'dmesg' command)
-A INPUT -m limit --limit 5/min -j LOG --log-prefix "iptables denied: " --log-level 7

# Reject all other inbound - default deny unless explicitly allowed policy:
-A INPUT -j REJECT
-A FORWARD -j REJECT

COMMIT

保存退出后，使规则生效


 iptables-restore < /etc/iptables.test.rules

当出现类似如下错误
iptables-restore v1.4.14: no command specified
Error occurred at line: 38
Try `iptables-restore -h' or 'iptables-restore --help' for more information.

则是文档格式问题，将文档格式转换为unix格式，再直接导入到Debian中

查看规则
iptables -L


iptables-save > /etc/iptables.up.rules

生效后编辑

nano /etc/network/if-pre-up.d/iptables

加入


#!/bin/sh
 /sbin/iptables-restore < /etc/iptables.up.rules

保存退出


chmod +x /etc/network/if-pre-up.d/iptables

重启即可