Double NAT Issue

[dlakelan]

But your core idea is correct, simplify and correctly set up the networks, so that each subnet is separated and in a proper private IP subnet (not public) and so each router knows the routes to each of the subnets it's connected to, and no overlap in addresses between subnets... then everything will work.

[mikma]

@psherman

I agree with @jezzaaaa that you shouldn't need a static route. Fundamentally, a router really only needs to know the network it controls and how to get to the network above (the gateway address)... in this case, it should theoretically forward packets appropriately up the stack.

Yes, that's the case if you use NAT on each cascaded router. But without NAT a static route is needed for the network(s) that can't be reach via the default gateway but via another path, i.e. "down the stack".

BTW when connecting multiple routers without NAT it's better to connect them with dedicated interface(s) instead of using LAN interfaces. The latter can cause asymmetric routing which will be a problem when using the stateful firewall rules in openwrt.

[jezzaaaa]

@mikma

Yes, that's the case if you use NAT on each cascaded router. But without NAT a static route is needed for the network(s) that can't be reach via the default gateway but via another path, i.e. "down the stack".

Good point @mikma. I just assumed that NAT was enabled on all of the routers. If that's not the case, then routing might be an issue.