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Quintin
Asked: 2011-11-06 07:47:26 +0800 CST

Two network adapters with the same ip

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I have two network adapters that use the same ip range, but are different networks.

I tried this but it didn't work:

iptables -t nat -A OUTPUT -p all -d 1.2.3.0/8 -j DNAT --to-destination 192.168.0.0/8 -o eth0
iptables -t nat -A OUTPUT -p all -d 3.2.1.0/8 -j DNAT --to-destination 192.168.0.0/8 -o eth1

Example:

eth0 has the ip of 192.168.0.1 on a network with the range 192.168.0.*

eth1 has the ip of 192.168.0.8 on a separate network with the range 192.168.0.*

1.2.3.* = 192.168.0.* through eth1

3.2.1.* = 192.168.0.* through eth0

Is this something I can do with iptables?

networking internet iptables ethernet eth0

2 Answers

  1. Best Answer

    Your question is not clear, but assuming you want to route your 1.2.3.4 traffic to one NIC and 4.3.2.1 to another than you need to update you routing table using route command.

    Example :

    route add -net 1.2.3.4 netmask 255.0.0.0 dev eth1
route add -net 4.3.2.1 netmask 255.0.0.0 dev eth0
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  2. You would either have to write code specifically to do this or add 512 individual NAT rules. The DNAT module treats multiple IPs as a round-robin, not a mapping.

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