IN> BTW this causes trouble with the FTP client in AIX which tries
IN> an AAAA lookup first and waits over a minute before trying an
IN> A if it doesn't get a response.
FG> If the resolver gets an "ICMP port unreacheable", it'd return
FG> an error to the FTP client, [...]
Not necessarily. If it hasn't connect()ed the UDP socket (but is just using
sendto() instead) it may not even receive any error indication to pass along.
FG> Are you sure you get an ICMP error because of the request for
FG> AAAA record?
I can confirm his report. DNS/UDP datagrams containing "AAAA" queries sent to
either 220.127.116.11 or 18.104.22.168 will elicit ICMP "port unreachable"