一、内核配置 /usr/src/sys/i386/conf/HQ_SuperServer
代码: | options IPFIREWALL options IPFIREWALL_DEFAULT_TO_ACCEPT options IPDIVERT # IPDIVERT enables the divert IP sockets, used by ''ipfw divert'' options IPFIREWALL_VERBOSE options IPFIREWALL_VERBOSE_LIMIT=30
#options IPFILTER #ipfilter support #options IPFILTER_LOG #ipfilter logging
# traffic shaper, bandwidth manager and delay emulator options DUMMYNET # enables the "dummynet" bandwidth limiter. You need IPFIREWALL as well. # Statically Link in accept filters for a web server on this box options ACCEPT_FILTER_DATA options ACCEPT_FILTER_HTTP options ICMP_BANDLIM # D.O.S. protection options IPSTEALTH #To hide firewall from traceroute options TCP_DROP_SYNFIN #To hide from nmap OS fingerprint, remove if create web server |
二、rc.conf配置 /etc/rc.conf
代码: | firewall_enable="YES" firewall_logging="YES" firewall_script="/etc/rc.firewall" firewall_quiet="NO" #change to YES once happy with rules firewall_logging_enable="YES"
#extra firewalling options log_in_vain="YES" #This option prevents something known as OS fingerprinting, must have TCP_DROP_SYNFIN compiled into kernel to use tcp_drop_synfin="NO" #change to NO if create webserver tcp_restrict_rst="YES" icmp_drop_redirect="YES" |
三、ipfw使用
代码: | ipfw add allow tcp from to in recv |
添加和除去规则例子:
代码: | $ sudo ipfw add deny tcp from 61.49.203.115 to 61.49.203.114 22 in recv fxp0 $ sudo ipfw -t list $ sudo ipfw delete 00100 |
禁止icmp
代码: | $ sudo ipfw add deny icmp from any to any in recv fxp0 |
显示rules
按照序号显示规则
列出信息包的数目,和与它们相对应的规则匹配
四、/etc/ipfw.rules规则文件
代码: | allow 00010 udp from any to me 67 in via $iif allow 00020 udp from me 68 to any out via $iif |
五、/etc/rc.firewall脚本
代码: | # mv /etc/rc.firewall /etc/rc.firewall.orig # touch /etc/rc.firewall # chmod u=+rx,og=-rwx /etc/ipfw.rules |
/etc/rc.firewall
代码: | #!/bin/sh
# This will flush the existing rules - sudo ipfw -f flush # You can execute this script without dropping existing connections/states
fwcmd="/sbin/ipfw -q" extif="fxp0" myip="10.1.8.114" mybcast="10.1.8.119" mynetwork="10.1.8.112/29" dns_server="10.1.8.1"
# Reset all rules in case script run multiple times ${fwcmd} -f flush
${fwcmd} add 200 check-state
# Block RFC 1918 networks - the , syntax only works in ipfw2 ${fwcmd} add 210 deny all from 0.0.0.0/7,1.0.0.0/8,2.0.0.0/8,5.0.0.0/8,10.0.0.0/8,23.0.0.0/8,/ 27.0.0.0/8,31.0.0.0/8,67.0.0.0/8,68.0.0.0/6,72.0.0.0/5,80.0.0.0/4,96.0.0.0/3,127.0.0.0/8,/ 128.0.0.0/16,128.66.0.0/16,169.254.0.0/16,172.16.0.0/12,191.255.0.0/16,192.0.0.0/16,/ 192.168.0.0/16,197.0.0.0/8,201.0.0.0/8,204.152.64.0/23,224.0.0.0/3,240.0.0.0/8 to any
# Allow all via loopback to loopback ${fwcmd} add 220 allow all from any to any via lo0
# Allow from me to anywhere ${fwcmd} add 240 allow tcp from ${myip} to any setup keep-state ${fwcmd} add 260 allow udp from ${myip} to any keep-state ${fwcmd} add 280 allow icmp from ${myip} to any
# Allow local LAN to connect to us ${fwcmd} add 300 allow ip from ${mynetwork} to ${mynetwork}
# Allow INCOMING SSH,SMTP,HTTP from anywhere on the internet ${fwcmd} add 320 allow log tcp from any to ${myip} 22,25,80 in keep-state setup
# Disable icmp ${fwcmd} add 340 allow icmp from any to any icmptype 0,3,11
# Block all other traffic and log in ${fwcmd} add 360 deny log all from any to any
# End of /etc/rc.firewall |
六、 ipfw日志纪录配置
/etc/syslog.conf
代码: | !ipfw *.* /var/log/ipfw.log |
代码: | $ sudo touch /var/log/ipfw.log $ sudo killall -HUP syslogd |
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