PUzzling sshd behaviour

[Dwayne MacKinnon]

Hi,

I recently took one of our machines off the main network and set up  a 
crossover cable between it and my personal box. I was looking to scp 
some large files over and I didn't want to swamp the network. (I use scp 
from force of habit, even though ftp would probably be quicker in this 
case.)

Long story short, I discovered that if there was a nameserver listed in 
resolv.conf on the isolated box, sshd would always try to do a reverse 
address mapping. As you'd expect, this hangs the login for a while. This 
  lookup occurs despite the fact that I 1) explicitly stated the 
no-reverse-mapping options in the sshd_conf, 2) invoked sshd with the 
-u0 flag and 3) put both the machines on this tiny private network into 
/etc/hosts.

Anyone else see this type of thing before? I did some research on the 
lists but all I ever saw was a problem with reading resolv.conf. That's 
not the case here, because it's definitely picking up the nameserver 
from that file.

Thanks,
DMK