Comment 9 for bug 1786799

If spaces aren't being used, it's easy to start using them. So I don't think that's a big concern. I think starting out with a spaces-based selection will get us 80-90% there. The (non-mutually-exclusive) alternatives to using spaces, which could be used for the other 10-20% of use cases, would be:

(1) Allow specific configuration of default DNS on a per-node basis. (I agree this should be done - in addition to spaces - but it's a much more cumbersome approach at scale.)

(2) Allow customization of the selection algorithm as a global setting. For example, we could have options such as "Prefer PXE network for DNS" vs. "Prefer default gateway network for DNS", etc.