Delay when logginng in to FC5 via ssh

[Karl Larsen]

Don Russell wrote:
> From a Windows PC I use an ssh client to log into my FC 5 box.
>
> There is always a delay after the initial connection before being 
> prompted for my password. The delay is around 15 seconds.
>
> Once I'm logged in, there's no delay, command responses are quick.
>
> The FC 5 box is 10.10.10.250, and th Windows PC is 10.10.10.24.
>
> If I add 10.10.1.24 to /etc/hosts on FC5 then there is no delay when 
> logging in.
>
    This is normal operation. Your getting ahead of your self. Do not 
put the other computers in FC5. Just connect without and the second 
connect will be much faster and the third faster yet.
> So, I conclude that ssh is trying to determine the host name of the 
> machine connecting to it, based on the connecting machine's IP address.
>
    No. What happens is the first time you connect it asks you if you 
want this to happen. You say yes. Then you use the proper password and 
files fly between the computers saying this IS a trusted link.
> I don't think it's actualy ssh related because I experince a similar 
> delay if I telnet to port 25 to my smtp server:

    Nope different thing altogether.
> If my 10.10.10.24 address is in /etc/hosts, the "220... reply banner" 
> is displayed immediately, otherwise there is a long delay.
>
> I have SELinux in permissive mode, so nothing magical should be 
> blocked due to that.
>
> The problem is, it is not practical to code all my private addresses 
> in /etc/hosts. The network clients use dhcp so of course their 
> addresses may change.
>
    Don't put ANY in /etc/hosts/.
> Can someone point me in the right direction of what to read up on... 
> it's not an ssh problem, it's not a sendmail/smtp problem, it's 
> somewhere lower than that... dns?
>
    You don't have a problem.

Karl

> I'm certain that if I can solve the ssh-delay issue, that will also 
> fix the telnet/smtp issue.
>
> Thanks :-)
>
>