On 10/26/07, Jeff - <unix_core@xxxxxxxxxxxxx> wrote:
I'm having many unsolvable problems using tun so I thought I'd try tap.
Yep, that's right. br0 is a virtual ethernet interface that combines the eth0 and tap0 physical interfaces. Only br0 gets an IP address.
When I run OpenVPN on the server and try to connect to it I get an error writing to UPDv4. Network is unreachable (code 101)
I am no expert here, but it sounds as though you are trying to route the VPN transport traffic over the VPN itself. Try connecting and then look at the output of 'route -n'. Check that there is not a default route that puts traffic over the VPN. If there is, figure out where it is coming from and disable it.
What am I missing?
I do this on a debian 4 system. In /etc/network/interfaces I have this stanza:
iface br0 inet static
This means: Set up a bridge interface br0 with the static address 192.168.2.1 and make it incorporate the eth1 physical interface. The 'auto br0' line means to bring it up when the system boots. I then use a script run with the --up option to openvpn to execute 'brctl addif br0 tap0' so that the tap0 interface is added to the bridge when it becomes present (ie. when the VPN is up).