Seth Mattinen wrote:

I've been trying to do some whois lookups around 22:00 Pacific time, and whois.arin.net doesn't seem reachable at 2001:500:4:1::81 . Can anyone else out there confirm, or is it just me?

I figured it out; return traffic coming back to me through Hurricane Electric was being dropped for whatever reason. I shut off my BGP session with them and it started working right away. ~Seth