On Sun, 09 Feb 2014 19:33:49 +0000 Timothy Murphy gayleard@eircom.net wrote:
I have OpenVPN set up; I found the brief instructions that come with CentOS openvpn (eg /etc/openvpn/2.0/README) perfectly adequate - what I'm asking about is the _use_ of OpenVPN.
Sorry, what exactly are you asking for here? The implemented OpenVPN is nothing but a (virtual, distributed, etc...) LAN. Imagine several hosts connected together with a switch and a bunch of ethernet cables. It is used in the same way an ordinary LAN can be used.
Imagine having several computers connected in a local network. How do you "use" this LAN? Well, you can ssh/ftp/ping among hosts, you can deploy various services among them (dns, nfs, samba, apache, mta, gaming servers, whatever...), and so on. The network is *virtual* in the sense that there are no physical cables and switches connecting the nodes directly. It is *private* because all communication is encrypted. But other than that, a VPN is simply a *network*, like any other network, and can be used in all the ways an ordinary network can.
An additional usage point is managing access certificates --- if you share your VPN with other people, you can issue certificates to all people who are supposed to join the network, revoke certificates from people you want to kick out of the network, etc.
One obvious benefit of VPN is that the nodes can be widely distributed geographically, while still connected into a single (virtual) LAN. It is also completely immaterial how is any given node physically connected to the Internet --- VPN is transparent to firewalls, NAT-s, etc.
HTH, :-) Marko