Which low cost server device is compatible with iOS VPN on demand? There is a question on "What is VPN on demand, and how do I get it to work with iOS?", however its accepted answer lacks detail.

Envision a small business usage with only 1 or 2 iPhone/iPad devices needing VPN on demand access. This scenario has a preference for low cost and maintenance, for example it prefers an entry level device with low power consumption, self-signed certificates with long expiry dates.

Which hardware and (specific) firmware, licenses, external certificates, modules, etcetera on the Cisco IPsec compatible routing device are needed?

To make the question more concrete, which of these Cisco VPN boxes would be sufficient?


RVS4000
RV180
RV042


And are there step-by-step configuration setup guides, starting from how to create the Cisco IPsec authentication certificate on that device, to creating the corresponding profile in the Apple configuration utility?
A Cisco box is not required, as there is the open source StrongSwan.

Only a device that is able to run Linux (Debian, Ubuntu, etcetera) is sufficient.

FreeBSD or MacOSX are not ok as those builds only support IKEv2 only, and the iOS built in client needs IKEv1.

Here is how to setup the iOS device for StrongSwan:
http://wiki.strongswan.org/projects/strongswan/wiki/IOS_%28Apple%29