A couple of my v6-capable machines don't seem to be listed in a 
functional reverse name server.  That is, there is no working server 
that maps IPv6 addresses to host names.  (Yes, I'm trying to deal with 
that.)  Worse yet, as best I can tell there's a non-functional server; 
attempts to resolve the PTR record time out.  This in turn causes 
problems with using ftp -- the ftp server on ftp.netbsd.org tries to 
look up the name; it takes sufficiently long to fail that (as best I 
can tell) my client times out: ftp.c seems to have a fixed 60-second 
timer before it gives up on the connection.

I'm not certain how best to fix this.  Clearly, I should try to get my 
name server fixed.  The odds on that happening are, I think, reasonable.
Others won't be that lucky.  Should we fix the timers on our ftp 
server?  On our clients?  Both?

		--Steven M. Bellovin, http://www.cs.columbia.edu/~smb