Exposing multiple virtual machines to public Internet from laptop on any connection

Question

I've got a couple of Ubuntu virtual servers on my laptop that I drag around with me and use to test configuration and interaction of services like mail, directories, etc. I therefore want to make them as much like my real server (out on the Internet) as possible, so they can talk SMTP, LDAP, etc. to other Internet-connected hosts. This way, I can test what's going to happen before I commit changes to the main server...

Assuming I'm on a random broadband connection, how can I get traffic to these servers from the Internet? I'm not on a single connection, so can't forward ports on a particular router. I'm wondering, though, if I can use some sort of VPN service to tunnel traffic from whatever connection I'm on to some public endpoints I can give DNS entries to.

(I'm aware that if I were just after web development, I could do a lot of stuff differently and serve it locally, etc., and that the machines will only be online when my laptop is connected; that's not a problem.)

Answer 1

You might consider using an external host (e.g. some "virtual private server" product in public IPv4 address space), set up a VPN connection from your machine to this host and perform port forwarding. A similar question on how to implement that kind of functionality has been asked just shortly.

DynDNS and other dynamic DNS services would only work as long as your laptop would be guaranteed to get a public IPv4 address. This would regularly not be the case in most corporate networks, when accessing the net through a wireless hotspot or through cellular networks.

Answer 2

Look into DynDNS or other similar services. With DynDNS they offer a nice client that will update the IP for where your computer is at when you move about. More details here: DynDNS client uodater