Hi,
Quoting UDNS:
"Most applications that requires asyncronous DNS processing either implements 
their own resolver modules (which, again, is not a trivial task, and sometimes 
leads to incompatibilities with other resolver libraries and bugs which are 
difficult to find), or uses forked-resolver model, where separate process is 
forked just to perform DNS queries, which requires quite some resources, 
especially when an application already have some sort of event loop in place 
to multiplex I/O. Asyncronous DNS resolver is a must for many nowadays 
applications, such as GUI (GUI-application should not stop processing user 
interface events while performing DNS queries), high-performance servers (such 
as mail servers) using event-loop model (see for example an excellent "The 
C10K problem" page at kegel.com describing various methods to handle many 
client requests in parallel)."
So you are forewarned it is not a trivial task. :( Then again what do we need? 
Reading documentation on most libs reveals that the problems start with the 
other stuff, not so much with A_NAME and AAAA_NAME records. But then again, 
when that part is not too hard, why not use an available library for that that 
is at least good at that?
Thanx,
Jaap
Stephen Fisher wrote:
All very interesting alternatives to adns.  I found a few others 
searching the Internet.  Why is everyone starting but not maintaining an 
async dns library? :) I don't like adns because it isn't maintained very 
much, but I'm afraid of trying something else and it being less stable.
Maybe this is something we should build into Wireshark since it is such 
an important feature?  Lots of work I'm sure.  What made me think of 
this was running across old web pages talking about Netscape and its 
built-in(?) async dns resolver ;).
Steve