OpenVPN does this by default. It always assigns the same IP based on
the client certificate. That mapping is stored in
/etc/openvpn/ipp.txt
Here is some documentation I have been working on. I see I didn't
explain that part very well.
http://www.qsl.net/kb9mwr/wapr/tcpip/openvpn.html
73'
Steve, KB9MWR
------Quote------
I was wondering if it were possible for a VPN server package to
consistently assign a specific, reserved IP address to a VPN client based
on the authenticating certificate.
The scope of the VPN server would be subject to the region/subnet coordinating
contact, such as a portion of:
Gateway area: 44.80.32/24 Central Pennsylvania
Thanks for your consideration.
73,
Jim A.
KB3TBX