Difference between revisions of "Cluster der kan alt/Routning og NAT"

From Teknologisk videncenter
Jump to: navigation, search
(Created page with "=Routning & NAT=")
 
m
Line 1: Line 1:
 
=Routning & NAT=
 
=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:
 +
#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
 +
# 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.

Revision as of 13:25, 18 April 2012

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.