Zdraveite, nqkoi moje li da mi helpne malko s iptables...
 znachi iskam vhodniq internet na eth0 da se preprashta na
 eth1 , a zad eth1 stoqt oshte 20 pc-ta... ako moje da mi
 kajete kak da si napravq edin firewall za taq cel... pod
slackware 10

echo "1" > /proc/sys/net/ipv4/ip_forward - така пускаш 
суитчинга между картите, 
за фиревал или си напиши сам в зависимост от това какво 
искаш да прави, или си дръпни от нета скрипт,  
20те комп-а трябва да се маскират като излизат от рутер-а, 
или не е така ? По темата има писано много !

 axm to mi e qsno ko tra da stane napisah si edno
firewall-che ama switching-a m/u eth0 i eth1 lipsva :(

echo "1" > /proc/sys/net/ipv4/ip_forward

iptables -t nat -A POSTROUTING -o eth1 -j MASQUERADE


Където eth1 ти е външната ланка.

znachi firewall-a mi e sledniq... i pak nestava :(

 echo "echo 1 > /proc/sys/net/ipv4/ip_forward" >>
/etc/rc.d/rc.local 

echo "/sbin/ifconfig lo 127.0.0.1" > /etc/rc.d/rc.inet1 

 echo "/sbin/route add -net 127.0.0.0 netmask 255.0.0.0 lo"
>> /etc/rc.d/rc.inet1 

 echo "/sbin/ifconfig eth0 192.168.1.111 netmask
255.255.255.0 up" >> /etc/rc.d/rc.inet1 

 echo "/sbin/route add default gw 192.168.1.1" >>
/etc/rc.d/rc.inet1 

 echo "/sbin/ifconfig eth1 10.0.1.1 netmask 255.255.255.0 up"
>> /etc/rc.d/rc.inet1 

echo "/usr/sbin/iptables -F" > /etc/rc.d/rc.firewall 

 echo "/usr/sbin/iptables -F -t nat" >> /etc/rc.d/rc.firewall


 echo "/usr/sbin/iptables --table nat --append POSTROUTING
 --out-interface eth0 -j MASQUERADE" >> /etc/rc.d/rc.firewall


 echo "/usr/sbin/iptables --table nat --append POSTROUTING
 --out-interface eth1 -j MASQUERADE" >> /etc/rc.d/rc.firewall


 echo "/usr/sbin/iptables -P FORWARD DROP" >>
/etc/rc.d/rc.firewall 

 echo "/usr/sbin/iptables -A FORWARD -s 10.0.1.2/32 -j
ACCEPT" >> /etc/rc.d/rc.firewall 

 echo "/usr/sbin/iptables -A FORWARD -d 10.0.1.2/32 -j
ACCEPT" >> /etc/rc.d/rc.firewall 

echo "sh /etc/rc.d/rc.firewall" >> /etc/rc.d/rc.local 

echo "nameserver 192.168.1.2" > /etc/resolv.conf 

chmod u+x /etc/rc.d/rc.firewall