1)
Fedora
ifconfig eth0_rename 1.1.1.254 netmask 255.255.0.0

Windows
ip : 1.1.1.1
gw : 1.1.1.254
dns : 10.16.0.2

Fedora
/etc/init.d/iptables restart
echo 1 > /proc/sys/net/ipv4/ip_forward

2)

iptables -t nat -A POSTROUTING -j SNAT --to-source 10.6.6.82

LIST RULES(iptables -t nat -L POSTROUTING)

- Faz alterações a porta de destino e origem

3)

iptables -t nat -A POSTROUTING -j SNAT --to-source 10.6.21.1-10.6.21.5