ipfw 防火墙配置学习笔记

ipfw是BSD系统中重要的防火墙和通信控制工具，在MacOSX中也很好用。先简单贴几个用法，有空再补上：

列出配置表

ipfw list

禁用ping，即ICMP协议

ipfw add 3333 deny icmp from any to any via en0

取消，则用

ipfw del 3333

* 续
ipfw重启之后就失效了，为了使每次开机都有效，需要加入到启动服务器中，下面是MacOSX下的一个配置例子：
1. 将ipfw规则写入自定的配置文件，例如/etc/rc.firewall

#!/bin/sh

IPFW='/sbin/ipfw -q'


$IPFW -f flush
$IPFW add 2000 allow ip from any to any via lo*
$IPFW add 2010 deny log ip from 127.0.0.0/8 to any in
$IPFW add 2020 deny log ip from any to 127.0.0.0/8 in
$IPFW add 2030 deny log ip from 224.0.0.0/3 to any in
$IPFW add 2040 deny log tcp from any to 224.0.0.0/3 in
$IPFW add 2050 allow log tcp from any to any out
$IPFW add 2060 allow log tcp from any to any established
$IPFW add 2070 allow log tcp from any to any 22 in
$IPFW add 2080 allow log tcp from any to any 80 in
$IPFW add 2090 allow log tcp from any to any 427 in
$IPFW add 12190 deny log tcp from any to any

以上配置规则适合个人web服务器管理，并开启远程ssh登录管理端口。摘自：
http://www.macdevcenter.com/pub/a/mac/2005/03/15/firewall.html

2. 建立目录/Library/StartupItems/Firewall，并在Firewall中创建两个文件：Firewall和StartupParameters.plist。设置属性：

chmod ug+x Firewall StartupParameters.plist

Firewall脚本内容如下：

. /etc/rc.common

StartService ()
{
  if [ "${FIREWALL:=-NO-}" = "-YES-" ]
  then
    ConsoleMessage "Starting Firewall"
    sh /etc/rc.firewall > /dev/null
  fi
}

StopService ()
{
  ConsoleMessage "Stopping Firewall"
  /sbin/ipfw -f -q flush
}

RestartService ()
{
  StopService
  StartService
}

RunService "${1:-start}" #默认参数为-start

StartupParameters.plist配置内容如下：

{
Description = "Firewall";
Provides = ("Firewall");
Requires = ("Network");
OrderPreference = "None";
Messages =
   {
   start = "Starting NAT/Firewall";
   stop = "Stopping NAT/Firewall";
   };
}

3. 设置/etc/hostconfig，在最底下增加一行：

FIREWALL=-YES-

使/Library/StartupItems/Firewall/Firewall的启动脚本能执行启动ipfw服务。

4. 测试

/Library/StartupItems/Firewall/Firewall start