[CentOS] SSH slow

Tue Jan 19 10:14:42 UTC 2010
Timo Schoeler <timo.schoeler at riscworks.net>

On 01/19/2010 12:26 AM, Les Mikesell wrote:
> ML wrote:
>> Hi All,
>> 
>> All of my systems are running 5.4 x64. The are all AMD x64
>> processors with at least 2gb of RAM in each.
>> 
>> I am running SSH on a non standard port.
>> 
>> When I SSH into ANY of my systems, I get prompted for my password
>> right away, but after entering, it takes 30+ seconds to get logged
>> in and get a prompt so I can work.
>> 
>> I dont quite know what to look for here
>> 
>> Does anyone have thoughts?
> 
> That sounds like a failing reverse DNS lookup or IDENT query dropped
> by a firewall so you wait for the timeout.

Try setting 'UseDNS no' in /etc/ssh/sshd_config.

HTH,

Timo