Ouch.. I didn't know it was doing this.. I'm guessing one of the tests is pinging the nameservers to exercise the "figure out my own IP address" function.
I've filed a bug upstream to track down the offending test and change it: https://foolscap.lothar.com/trac/ticket/263 I'll try to address that soon. We have a new release in the works, should be done in a few weeks. I know that Tahoe-LAFS is marked for autoremoval from testing on Aug 22nd because of this, and I really don't want that to happen :-). cheers, -Brian
