i need to configure a new router with DD-WRT, in my network, configured as gateway VPN.
My main gateway router is configured with ip Address 192.168.1.254, Subnet 255.255.255.0. It act also as DHCP that release 192.168.1.x address class.
The 2nd router with DD-WRT is configured with ip address 192.168.1.10. Then i configure VPN as described like image 2. The Problem is both pc1 or pc2 if configured with gateway 192.168.1.10 can't go on internet.
What am i missing ?
From your gateway router, you must poke a few holes in the firewall, and possibly enable some firewall modules. From the picture you posted, it looks like you're trying to setup l2tp, which usually is mixed with IPSEC. Both of which require forwarding more than just a few ports. IPSEC requires 2 protocols to be permitted through, as well as a port. You must permit AH (protocol 51) as well as ESP (protocol 50) as well as udp port 500. Openwrt has a great wiki page just for that.
If your gateway router is not running openwrt, usually you can find an option labled "ipsec passthrough," "vpn passthrough" or something similar. In openwrt, you'll need to install the iptables-mod-ipsec package to permit iptables to keep track of ipsec connections. (Without it, you will be limited to 1 connection)
Once IPSEC is permitted in, l2tp will make use of the encrypted data stream to tunnel layer 2 communications between the endpoints.
I solved. Simply, the problem, was the version installed of DD-WRT. I tried another version and worked without any problem. So there aren't any networking problem.