As far as I can see, for the broadcast protocols to work you need to use
the same subnet in both ends. The way I set a similar system up some
time ago was as follows:
|-------- Public Network -------|
| |
|-----------|-------------| |------------|-------------|
| eth0 (w.x.y.z) | | eth0 (a.b.c.d) |
| | | |
| gw.site1.company.com | | gw.site2.company.com |
| | | |
| br0 { eth1 tap0 } | | br0 { eth1 tap0 } |
|---------|---------------| |---------|----------------|
| |
10.74.2.0/24 10.74.2.0/24
Subnet of Redmond boxes Small remote subnet
DHCP server, etc. Client Redmond boxes
The important part here is that both sides are on the same subnet.
Note that OpenVPN isn't really configured with any IP addresses at all
(except the peer's) since it operates on the Ethernet level.
Redmond broadcasts to 10.74.2.255 will go over the bridge, as will DHCP
requests, since they are both also Ethernet broadcasts.
Some firewalling was also involved, but since it was done using the
ethX OS I'd rather forget all about it...
And yes, I've since gotten rid of both Redmond and the ethX OS, and also
bridging, since the need disappeared with the Redmonds, so I might have
forgotten things along the way.
--
Jussi Peltola
