Just wanted to send a quick reminder about Linux kernel compatibility for UCP Beta. As of the most recent version (UCP 0.7.1), UCP is compatible with Linux kernel version 3.10 and above.
Previous versions of UCP required the --old-kernel flag to work below kernel 3.16 and did not enable the multi-host networking capability. However that is no longer the case with the current version. This flag has been removed, and kernels 3.10 and greater should now function with multi-host networking.