vtund Experimentation part 3 - Bridging

Picking up from "vtund Experimentation part 2" we are going to set up the bridge interface, which will bridge tap0 and eth1 as depicted in http://blog.kovyrin.net/2006/04/05/connecting-two-remote-local-networks-with-transparent-bridging/ (although there it's eth0).

On both server and client sever the vtund connection (if any) and kill the vtund process.

On the server:
in the lion config of vtund-server.conf, replace
"ifconfig "%% 10.1.0.1 netmask 255.255.255.0";
with the following lines:
ifconfig "%% up";
program "brctl addif br0 %%";
comment out the route command.
change the password (recommended)

On the client:
in the lion config of vtund-client.conf, replace
"ifconfig "%% 10.1.0.2 netmask 255.255.255.0";
with the following lines:
ifconfig "%% up";
program "brctl addif br0 %%";
change the password to same as server's (if changed on server).

On the server:
in /etc/network/interfaces
remove the eth1 ip configuration, except for the line
auto eth1 # to bring up eth1
Add the br0 ip configuration:
iface br0 inet static
address 192.168.100.99
netmask 255.255.255.0
bridge_ports eth1

On the client:
in /etc/network/interfaces
remove the eth1 ip configuration, except for the line
auto eth1 # to bring up eth1
Add the br0 ip configuration:
iface br0 inet static
address 192.168.100.100
netmask 255.255.255.0
bridge_ports eth1

On both server and client bring up br0:
ifup br0

On the server:
vtund -n -s -f /etc/vtund-server.conf

Then on client:
vtund -n -f /etc/vtund-client.conf lion server_public_ip_address

With luck, a UDP connection (tunnel) will be initialized. From client you should be able to ping 192.168.100.99 (server's br0 ip address).

On the server, type
brctl show
results:

bridge name bridge id STP enabled interfaces
br0         xxxxxxxx  no          eth1
                                  tap0

Now set up another machine on the 192.168.100.x network on either side and ping both machines from it. If the machines can't ping eachother, ensure that the switch (vSwitch if in VMware) is set to Accept in Promiscuous Mode Policy Exceptions.

(see also Building Linux Virtual Private Networks (VPNs) on Google Books for example of the Ethernet Tunnel)