I recently used this answer to configure a DNS server for my virtual machine network, and I thought the answer went far and above in it's readability and thoroughness.
Why can't I vote for this with rep from a different site? This answer to a similar question seems to imply that there are trolls who go to extreme lengths to upvote themselves, so I understand the need for some controls. My question, though, is not why can't I vote with no reputation, but why my reputation from a different site (Stack Overflow), can't be ported over to allow me to at least upvote or comment? I can't even post this question on Ask Ubuntu meta!
It is somewhat sad to me that the DNS answer only has a 49 rating (at the time of this post), and I believe that part of that at least is that the reputations from Stack Overflow or Server Fault can't be used to vote.