Cluster der kan alt/Routning og NAT

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Routning & NAT

Configuring NAT (Sharing Internet)

For this, we do not need to install anything new. Everything is right there but is currently disabled. First, edit /etc/sysctl.conf. Find this:

  1. net.ipv4.ip_forward=1

Uncomment it by removing the #. Now forwarding is enabled in the system kernel. Now write: iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE What this does is make a NAT rule for post-routing. It sets the eth0 as the output card (The one out to the internet) and sets source to it's own IP through MASQUERADE. Then write: echo 1 > /proc/sys/net/ipv4/ip_forward This will enable it without a reboot. Just to be sure, save it. iptables-save > /etc/iptables.rules Now that it’s saved we need to load the iptables.rules on starting the network: vi /etc/network/interfaces

  1. The extended interfaces

auto eth0 iface eth0 inet dhcp pre-up iptables-restore < /etc/iptables.rules post-down iptables-restore < /etc/iptables.rules Test it out on your other client.