[CentOS] Slow login to system without internet connection

Ljubomir Ljubojevic office at plnet.rs
Tue Nov 20 20:54:31 UTC 2012


On 11/20/2012 09:47 PM, m.roth at 5-cent.us wrote:
> Ljubomir Ljubojevic wrote:
>> On 11/20/2012 09:25 PM, Les Mikesell wrote:
>>> On Tue, Nov 20, 2012 at 12:48 PM, Ljubomir Ljubojevic <office at plnet.rs>
>>> wrote:
> <snip>
>>>> 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.
>>>
>>> Most server apps will do a reverse-DNS lookup, if only to log the name
>>> for the connection, some will try an ident query for the user at the
>>> other end of the socket.   A 30+ second delay is a pretty sure sign
>>> that one or more of the DNS servers in your resolv.conf did not
>>> respond.  Running a local nameserver with a dummy local domain is one
>>> way to fix it, but just putting all your local systems in the
>>> /etc/hosts file will work too.
> <snip>
>> So the question is: "is there a setting that will reduce that DNS
>> timeout for all running services, maybe like a ping-watchdog that would
>> recognize the problem and skip the reverse-DNS lookup if DNS servers are
>> not reachable?"
> <snip>
> What does it say in /etc/nsswitch: is it dns files, or files dns?

"files dns"
-- 

Ljubomir Ljubojevic
(Love is in the Air)
PL Computers
Serbia, Europe

Google is the Mother, Google is the Father, and traceroute is your
trusty Spiderman...
StarOS, Mikrotik and CentOS/RHEL/Linux consultant


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