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I have an odd setup where there is a router(Router 2) routing between network network 1 and network 2. One router(Router 1) with nat for internet access that routes between internet and network 1. There are people in both of these networks. All the clients in network 1 can access the internet, the clients in network 2 can access the clients in network 1 and can also access the router 1. Router 1 can also access clients in network 2.

However, the clients in network 2 cannot reach the internet. I cannot think about anything in the routing tables that would hinder this, since Router 1 can reach the clients in network 2 and vice versa. Can it be that nat starts the session between router 2 and the internet site/machine instead of the client and the internet machine? Does anyone have any ideas?

I have very little control over router 2(its basicly an ISP vpn net service) but full access to router 1. Its an ubuntu 10.04 with iptables for nat/firewall setup.

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First thought is that Router 2 does not know Router 1 is its default gateway?

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