Preventing ip conflicts in xen
Lately I was playing with stock xen kernel and virtualization, and I came across one relatively big problem. Let’s say I want to share my guest machines to, let’s say clients. You must give them root… because that’s whats VPS-es all all about, having root access to OS without having to purchase expensive hardware. Having that in mind they are by default untrusted and unpredictable, they can do god knows what in there!
So what caught my eye?
By default xen, and available management tools, don’t really have a way of sorting out IP conflicts in bridged mode. Basically you have bunch of scripts that will provision VPS alongside with IP address. Looking at the conf files you have vif and IP declarations in vm_xen.conf file.