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

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=Routning & NAT=
 
=Routning & NAT=
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Configuring NAT (Sharing Internet)
 +
 +
==Start Routing==
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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:
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<source lang=cli>
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net.ipv4.ip_forward=1
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</source>
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Uncomment it by removing the #. Now forwarding is enabled in the system kernel.
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===Start routing without a reboot===
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<source lang=cli>
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echo 1 > /proc/sys/net/ipv4/ip_forward
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</source>
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This will enable it without a reboot.
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==NAT==
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<source lang=cli>
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iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
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</source>
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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:
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Just to be sure, save it.
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<source lang=cli>
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iptables-save > /etc/iptables.rules
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</source>
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Now that it’s saved we need to load the iptables.rules on starting the network:
 +
 +
edit the file '''/etc/network/interfaces'''
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<source lang=cli>
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# The extended interfaces
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auto eth0
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iface eth0 inet dhcp
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pre-up iptables-restore < /etc/iptables.rules
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post-down iptables-restore < /etc/iptables.rules
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</source>
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Test it out on your other client.
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{{Source cli}}
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[[Category:cluster]][[Category:Ubuntu]]

Latest revision as of 14:31, 18 April 2012

Routning & NAT

Configuring NAT (Sharing Internet)

Start Routing

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.

Start routing without a reboot

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

This will enable it without a reboot.

NAT

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: 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:

edit the file /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.

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