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很多人反复在问Linux如何设置才能实现共享上网,干脆写一个步骤出来吧
1、vi /usr/local/sbin/firewall
- #! /bin/bash
- # Project by Platinum, 2005-05-12"
- # Set MODE (LAN or ADSL)
- MODE="ADSL"
- # Set default gateway (如果MODE==ADSL,此项可以忽略)
- GATEWAY="外网网关"
- # Set Interface WAN (如果MODE==ADSL,此项可以忽略)
- WAN_IP="外网IP地址"
- WAN_ETH="外网网卡"
- WAN_MASK="外网掩码"
- # Set Interface LAN
- LAN_IP="内网IP地址"
- LAN_NET="内网网络地址"
- LAN_ETH="内网网卡"
- LAN_MASK="内网掩码"
- # Set manager
- MANAGER_IP="内网管理员IP"
- MANAGER_MAC="内网管理员MAC"
- # Initialize modules
- modprobe ip_nat_ftp
- echo 1 > /proc/sys/net/ipv4/ip_forward
- # Initialize Interface LAN
- ifconfig $LAN_ETH $LAN_IP netmask $LAN_MASK
- # Initialize policy
- iptables -P INPUT DROP
- iptables -P FORWARD ACCEPT
- iptables -F
- iptables -t nat -F
- # Deny ACK attack
- iptables -A INPUT -p tcp ! --syn -m state --state NEW -j DROP
- iptables -A FORWARD -p tcp ! --syn -m state --state NEW -j DROP
- # Initialize Rules
- iptables -A INPUT -i lo -j ACCEPT
- iptables -A INPUT -i $LAN_ETH -s $MANAGER_IP -m mac --mac-source $MANAGER_MAC -j ACCEPT
- # Added in 2006.02.08, accept all icmp packets except echo-request rate 5/s
- # ========== begin ==========
- iptables -A INPUT -p icmp --icmp-type 8 -m limit --limit 5/s -j ACCEPT
- iptables -A INPUT -p icmp --icmp-type 8 -j DROP
- iptables -A INPUT -p icmp -j ACCEPT
- # =========== end ===========
- iptables -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
- case "$MODE" in
- LAN)
- # Initialize Interface WAN
- ifconfig $WAN_ETH $WAN_IP netmask $WAN_MASK
- iptables -t nat -A POSTROUTING -s $LAN_NET -o $WAN_ETH -j SNAT --to $WAN_IP
- ;;
- ADSL)
- iptables -t nat -A POSTROUTING -s $LAN_NET -o ppp0 -j MASQUERADE
- GATEWAY=`ifconfig ppp0|grep inet|awk '{print $3}'|awk -F: '{print $2}'`
- ;;
- esac
- ip route replace default via $GATEWAY
复制代码
2、chmod 700 /usr/local/sbin/firewall
只有root权限才能读写执行
3、echo "/usr/local/sbin/firewall" >;>; /etc/rc.local
让系统启动后自动执行脚本
4、reboot
重启系统
自己根据自己的情况改一下就可以了,应该不难懂
注意:
如果是直接设置IP上网,MODE选择LAN
如果是用PPPOE拨号上网,MODE选择ADSL,且保证在执行这个脚本之前已经拨号
[ 本帖最后由 platinum 于 2006-8-14 20:42 编辑 ] |
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