OpenVPN and Squid for the Holidays

Christmas vacation has started. For some of us who would like to do some work from home, Virtual Private Network(VPN) is the solution. In this entry, I'll describe the OpenVPN setup I made on an Ubuntu 10.04 Server.

The main requirement I'd like to address is to be able to connect to the office network (10.0.3.0/24) to which our development server(10.0.3.5) is attached. This development server is not public. Also, I would like to be able to access the online journals (ACMDL, Elsevier, SpringerLink,IEEE) which require IP address authentication.

The physical server is an Intel Pentium 4 CPU 2.80GHz with 512MB RAM and 
40GB disk space. It has two NICs, with one connected to the DMZ(public IP)  and another to the office network(with IP 10.0.3.252).

I installed Ubuntu Server 10.04 LTS then followed the steps here to install OpenVPN. Although, L2(Data Link) is described in the tutorial, I implemented L3(Network) which I think is simpler. After which, I added a static route in the office router (10.0.3.254) to allow the VPN clients (10.8.0.x) to access the office network.

ip route 10.8.0.0 255.255.255.0 10.0.3.252