head:~# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
201.xx.xx.0 201.xx.xx.1 255.255.255.0 UG 0 0 0 eth3
201.xx.xx.0 * 255.255.255.0 U 0 0 0 eth3
localnet head.furlan 255.255.255.0 UG 0 0 0 eth0
localnet * 255.255.255.0 U 0 0 0 eth0
200.xx.xx.0 200.xx.xx.1 255.255.255.0 UG 0 0 0 eth1
200.xx.xx.0 * 255.255.255.0 U 0 0 0 eth1
default 200.xx.xx.1 0.0.0.0 UG 0 0 0 eth1
default head.furlan 0.0.0.0 UG 0 0 0 eth0
head:~# cat f1r3
#!/bin/sh
LAN=eth0
LAN_CLASSE=192.168.1.0/24
LINK1=eth1
LINK2=eth3
GW1=200.xx.xx.1
GW2=201.xx.xx.1
MARK1=11
MARK2=12
T1=telefonica
T2=embratel
/etc/init.d/networking restart
echo "[Apagando regras]"
iptables -X
iptables -F
iptables -t nat -X
iptables -t nat -F
iptables -t mangle -X
iptables -t mangle -F
echo "[Ativando compartilhamento]"
ip rule add fwmark $MARK1 table $T1 prio 20
ip rule add fwmark $MARK2 table $T2 prio 20
ip route add default via $GW1 dev $LINK1
ip route append default via $GW2 dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
route del default dev $LINK2
ip route flush cache
iptables -A INPUT -p tcp --syn -s 192.168.1.0/255.255.255.0 -j ACCEPT
iptables -A POSTROUTING -t nat -s $LAN_CLASSE -o $LINK1 -j MASQUERADE
iptables -A POSTROUTING -t nat -s $LAN_CLASSE -o $LINK2 -j MASQUERADE