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I have a Linux router with 2 NICs doing masquerade from network to an ADSL router.

users <----> NIC A [router] NIC B <----> INTERNET

Now I'm experimenting with proxy arp on the NIC A to intercept all the IP requests in the network.

I have a pool of addresses in the network for this users.

How can I translate, saythe IP10.0.0.64to192.168.0.64` in order to grant it internet access?

I have already tried SNAT - DNAT, even I have written a NFQUEUE app to spoof the IP address with no luck.

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Do you have ip_forward enabled?

cat /proc/sys/net/ipv4/ip_forward

To enable it immediately:

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

To enable it permanently:

echo "/proc/sys/net/ipv4/ip_forward = 1" >> /etc/sysctl.conf
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