Is it a problem with openvpn or virtualbox ?

[cakemaker]

I'm trying to learn openvpn on vbox and encounter a strange problem.

My configuration:
vpn server is on a guest centos, use console mode
vpn client is on a guest ubuntu, use terminal in gui
I follow the HowTo step-by-step and pick the server-bridge approach

Current Situation:
After start up openvpn on both guests, I can see on the vpn client that the ip of tap0 is 10.8.0.50 (from result of ifconfig) which is allocated from the vpn server.
However, on vpn server, no ip (expecting 10.8.0.4, the sample default) of tap0 is found !?!
And, obviously, I cannot ping 10.8.0.4 from the vpn client, and go on my learning.

Did I make some fundamental network mistake when I use two vbox guests to do vpn? (sorry for my poor network knowledge)
Or, my situation can be resolved by some setting?

Thanks a lot for your advice.

[cakemaker]

Sorry that I posted it at a wrong section.

I intended to post it in the "Installation Help" section which I think should be more appropriate. I cannot do it myself now cause I find that I'm not allow to delete post here. Can any Power User help me to do it?

[Douglas]

Sorry that I posted it at a wrong section.

I intended to post it in the "Installation Help" section which I think should be more appropriate. I cannot do it myself now cause I find that I'm not allow to delete post here. Can any Power User help me to do it?

moved

[cakemaker]

Would anybody please give me some advice?
I have put aside it for two days, recheck those settings against the howto, but still cannot figure out what's wrong.
In fact, I did search "virtualbox"/"vbox" here before I made this post but that didn't help.

BTW, after I start openvpn, should I expect to see 10.8.0.4 at the tap0 section on ifconfig output on the openvpn server pc?

thanks