I have a small VPN network with a bunch of clients working mostly with each other and a VPN server. Everything works fine, except, obviously I can't shut VPN server down without breaking the network.

I have a spare machine, which worked as an VPN server for the same network before so it is signed with the same SA as the first one and basically configured just the same as the first one. Technically I can make my clients work with it with little adjustment (by setting remote in etc/openpvn/clientx.conf), but it would be great make this switch automated.

So basically I want two VPN servers running in the same network to work completely interchangeable without clients even knowing this. Can I do this with VPN or should I dig deeper into physical network layer?