???????????
????· ???IP?????·???????????????????????????????IP?????????????в????????
????· ????IP?????·?????????????????????п????IP?????
????· IPα?????????????л??????MASQ?????????????????????ЩMASQ?????????????????????????????MASQ??????????κ?????????????????????MASQ?????
????· ???????????NAT??????????IPα?????????????IP??????????????????
??????????
????· ???????????????????IP??????????????IP???????linux??????????????????????????
????· ??????????????IP?????linux/windows????PC?????????
????· ??????/???????????????
???????????????
????1??????IP???
??????????????繲??????????linux???????????????????????IP???????????????????趨??/etc/sysctl.conf????С?????????????λ??????"# net.ipv4.ip_forward = 0"??????У????#?????????????????????????1??
????????????IP?????????Ч?????????????????
????sysctl -w net.ipv4.ip_forward=1
????sysctl -p
???????????????????????Ч????????Ч
????echo "1" > /proc/sys.Net/ipv4/ip_forward #??IP?????1????????0????????
????2??NAT????
????????????繲????????????NAT????????????????iptables??????iptables???????????????????
????· FILTER (?????)
????· NAT
????· MANGLE
????· RAW
?????????????????????????????FILTER??NAT???
???????????????л?????????????
????iptables -X
????iptables -F
????iptables -t nat -X
????iptables -t nat -F
?????????????У?????????????????FORWARD??????????ACCEPT?????????????????????????????????????????
????iptables -I INPUT -m state --state RELATED??ESTABLISHED -j ACCEPT
????iptables -I FORWARD -m state --state RELATED??ESTABLISHED -j ACCEPT
??????NAT???У??????????WAN??????IPα?????????????WAN??Э????ppp0???????ppp0????????IPα????????????????μ?????
????iptables -t nat -I POSTROUTING -o ppp0 -j MASQUERADE  #???????????????????????ppp0????eth0
???????????????????????
????iptables -F
????iptables -P INPUT ACCEPT
????iptables -P FORWARD ACCEPT
????iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE #??NAT
???????????????(192.168.1.0/24????????Internet??????192.168.1.1)
????1??NAT??????
?????????????????????????
????eth0:192.168.1.10 ????255.255.255.0 ?????192.168.1.1 #????????Internet????
????eth1:192.168.2.1 ????255.255.255.0 #???????????
???????????192.168.2.10/24 ?????192.168.2.1 #??eth1?????Σ??????eht1
????2???????????
????eth0:0.0.0.0 #??IP -->br0
????eth1:0.0.0.0 #??IP -->br0
????br0:eth0:192.168.1.10 ????255.255.255.0 ?????192.168.1.1
???????????192.168.1.10/24
????ifconfig eth0 0.0.0.0 up  #???????????????·???????IP
????ifconfig eth1 0.0.0.0 up
????brctl addbr br0 #??????????
????brctl addif br0 eth0
????brctl addif br0 eth1 #??eth0 eth1??????????
????ifconfig br0 192.168.1.10.Netmask 255.255.255.0 broadcast 192.168.1.255 up #?????????IP????????????NAT?????????????????????????????IP????????????????????ifconfig br0 up??
????route add default gw 192.168.1.1 #?????????????????????????????????????????
???????????
????????NAT????????????????????????????????????????Щ???????????????????????????????????NAT??????????á?
?????????????????????wifi?????hostapd?????????????????ο?creat_ap.