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bridging just by dhcp

Posted: Mon Oct 19, 2015 11:48 am
by moerdock
Hello together,
I can't find helpfull documentation.

I use raspbian jesse ( and want to use openvpn to connect openvpn connections comming on lan 10.0.0.x (eth0) to internet (via wlan0).
wlan0 is connected to FritzBox "Gastzugang". That means the configuration on wlan0 is made by dhcp of the fritzbox to random network.

By that configuration I can use my laptop with single W-LAN-Adappter to connect simultaniously to a local network without internet access and a virtual network established over openvpn via local network for internet traffic. The virtual network for internet-traffic will only be connected to a VM on the laptop.

I found out instruction to configure it by tun and POSTROUTING to wlan0.
It doesn't work propably. I can connect and ping, but I don't come to internet.
However, even when it works the way to internet is not as free and transparent like when I use bridging.

So I want to use networkbriding instead.
By theorie it must be possible to create tap0 and connect it by br0 to wlan0 in the way, that a client connected to tap0 gets its configuration by the dhcp-server of the fritzbox (at wlan0). A switch/AP would manage it like that.

The clients virtual network adappter should get Network SSID "Fritz Gastzugang" and IP, netmask, gateway and DNS-Server by FritzBox and the FritzBox sees a client behind "raspberry-switch".

Every documentation I could find needs information about dhcp-range for the clients (using openvpn as dhcp-server) or at least the bridged network configuration. Do I need to get current dhcp information from wlan0 an configure my bridge at this data?

Thanks for help

Re: bridging just by dhcp

Posted: Tue Oct 20, 2015 1:42 pm
by Traffic
Please give an example of the DHCP IP address you are expecting to receive over the VPN for your client.

Re: bridging just by dhcp

Posted: Wed Oct 21, 2015 12:17 pm
by moerdock
Today the DHCP-Server (FritzBox "guest access") has the IP ( It located one Client by IP and the raspberry (wlan0) by IP So I would expecta client bridged (over vpn to raspberry wlan0) to recieve for example the IP

Tomorrow the DHCP-Server probably has the IP and will change the Client-IPs that way.

Re: bridging just by dhcp

Posted: Tue Nov 24, 2015 12:35 am
by Traffic
Setup OpenVPN and a bridge/TAP .. then let OpenVPN do DHCP for you: ... dging.html