Currently the LAN I manage is organized as follows: internal network (192.168.1.0) which uses a Linux server as a gateway (internal address on interface br0 192.168.1.1, external address on interface br1 10.0.0.2) through NAT; then the 10.0.0.0 network has another gateway (10.0.0.1) which through another NAT connects the whole thing to the internet. What I would like to achieve is to configure the Linux server so that the first layer of NAT is no more necessary, so that for example a computer in the 10.0.0.0 network can ping every computer in the 192.168.1.0 network. I deleted this iptables rule: iptables -t nat -A POSTROUTING -o br1 -j SNAT --to-source 10.0.0.2, but of course now computers on 192.168.1.0 cannot reach the internet; ip forwarding is of course enabled. What's missing here? Thanks