[SOLVED] How To Control DHCP Lease In OpenVPN

blueaquan

Hello Everybody
My OpenVPN configuration is working perfectly alright with Active Directory authentication. However, I noticed that the IP address that's assigned to the Client Machines from the Server is for a period of one Year.
Is there a way to control this Parameter? If yes, I would like to bring this down to one day. Could you kindly help?

Thanks

Blue

Mimiko

who is serving DHCP requests: OpenVPN or some other DHCP server? If OpenVPN - its not a problem. If some DHCP server on LAN - you have to configure it. It's out of scope of OpenVPN.

janjust

the 1 year DHCP lease is assigned by OpenVPN itself; it can be controled (on the CLIENT side for Windows clients using

ip-win32 dynamic [offset] [lease-time]

e.g.

ip-win32 dynamic 0 3600

blueaquan

Hi Mimiko and Janjust
The Lease is served by OpenVPN, however it would be great if there was a simpler way to do it on the OpenVPN Server rather than on individual client machines...

Thanks
Blue

janjust

In a 'tun' style network the DHCP lease is done by the OpenVPN *client*, not the server. The OpenVPN client program acts as a mini DHP client to the local tap-win32 adapter.
If you want to have a server side DHCP server then you need a 'tap' style network, possibly using bridging (which I would NOT recommend)

On the server side you might be able to get away with

push "ip-win32 dynamic [offset] [lease-time] "

blueaquan

Hi Janjust
I have a bridge mode setup on my Network with OpenVPN running on FreeBSD 8.0 serving Win XP clients. Therefore I should be able to use the option you mentioned in my "server.conf" file...?
Also what's the Offset parameter? Could you kindly give me an example please...?

Thanks
Blue

janjust

I've never tested if this works, but it just might: add

push "ip-win32 dynamic 0 3600"

to the server.conf file, restart the openvpn server and reconnect the clients.

blueaquan

Hi Janjust
Congratulations! it worked! I added the push ip-win32 directive to my server.conf file and the lease now shows one day.

Thanks to you and everybody in this thread.

Blue

janjust

great to hear that - this is one for the FAQs :ugeek:

closing topic.