Slow authentication

twantrd · 09-22-2004, 12:38 PM

Hi,

I have installed RHAS 3.0 on 4 machines and when I ssh into them and log in (supplying my username and password), it takes a long time (a good 5 seconds) before I am able to see the prompt. This happens on all 4 machines I have built. Has anyone noticed this too? Is there something I can do to eliminate this long latency? Thanks!

-twantrd

win32sux · 09-22-2004, 12:59 PM

i think you either need to make sure that the dns servers the boxes with the ssh daemons are using are fine, or use this line in the /etc/ssh/sshd_config file of the servers:

Code:

UseDNS no

twantrd · 09-22-2004, 06:20 PM

Thanks! That worked. However, why would DNS have an affect on login authentication? That makes me perplexed. Can you explain? Thanks!

-twantrd

chort · 09-23-2004, 12:21 AM

Because UseDNS causes sshd to attempt a reverse DNS lookup of every IP that initiats a connection. You didn't have PTR entries for the IPs you were connecting with. The delay was caused by the DNS lookup being performed and timing out.

twantrd · 09-23-2004, 02:29 AM

Ahhhhh! Thank you very much!

-twantrd