[CentOS] Slow login to system without internet connection

Hakan Can gogreenbecool at gmail.com
Fri Nov 23 06:55:19 UTC 2012


On 11/21/2012 09:44 AM, Peter Eckel wrote:
> Hi Ljubomir,
>
>> But when I tried to login to my server, it was not instantenous, and I
>> think it was 15+, maybe even 30+ seconds (I forgot to time it) from
>> start of ssh command to password prompt. It is in-house connection, so
>> there is nothing to traceroute.
>
>
> are you using an external DNS server that is reachable via the internet only?
>
> If so, edit /etc/ssh/sshd_config and change this
>
>    #UseDNS yes
>
> to
>
>    UseDNS no
>
> Then restart sshd and see whether it still happens. sshd tries to look up its counterpart's host name using DNS in the default setting, and if DNS is not reachable it waits for the request to time out.
>
> Best regards,
>
>    Peter.
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  "UseDns no" doesn't  solve the problem because  GSS Api needs reverse 
lookup.

If (do not need GSS Authentication) then
   put "GSSAPIAuthentication no" in the host /etc/ssh/sshd_config
else
  put your server ip and server name in the client  /etc/hosts
  "xxx.xxx.xxxx.xxx yourserver.name"
  :)

  H.can




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