I got it working. Had to fix some minor issues like matching mtu settings on the client and server. And if you dont add the tunnel's subnet as a local network in the server-manager correctly, it doesn’t work.
On the server, if you're setting it up for a single client:
#server.conf example
remote 1.2.3.4
ifconfig x.x.x.1 x.x.x.2
Then you need to add a local network into server-manager, like so:
Network address: x.x.x.0 (same subnet as ifconfig above)
Subnet mask: 255.255.255.0
Router: <ip addy of the internal nic of the server>
But, if you are setting it for multiple clients like this:
#server.conf example
mode server
server x.x.x.0 255.255.255.0
Then you have to use a subnet mask of 255.255.255.252 (4 addresses) or 255.255.255.248 (8 addresses, etc), in the server-manager when you add the local network:
Network address: x.x.x.0 (same subnet as x.x.x.0 above)
Subnet mask: 255.255.255.248
Router: <ip addy of the internal nic of the server>
If you don’t, you get this error when restarting openvpn:
[root@gate1 ~]# service openvpn restart
Shutting down openvpn: [ OK ]
Starting openvpn: RTNETLINK answers: File exists [ OK ]
That error might be caused by over-lapping addresses used by Openvpn’s dhcp service for the clients, but for whatever reason, you have to define the amount of ip addresses used.
Anyway, tiz cool, mon...