problem with dns

[Michał Piotrowski]

2009/10/22 Giovanni Tirloni <tirloni at gmail.com>:
> 2009/10/21 Michał Piotrowski <mkkp4x4 at gmail.com>:
>> Hi,
>>
>> This is a problem that touches some of Fedora services.
>>
>> I've got a network
>>
>> 192.168.101.0
>>
>> 192.168.101.1 - this is my router
>> 192.168.101.200 - ozzy - my F11 server
>> 192.168.101.100 - dio - my Windows 6 workstation
>>
>> I use two DNS servers
>>
>> nameserver 192.168.1.1
>> nameserver 194.204.159.1
>>
>> The problem shows up when my network 192.168.101.0 lose a connection
>> with 192.168.1.0 and my primary DNS server is not available.
>
> [...]
>
>> Every time when I try to use samba I get no response from ozzy. Here
>> is what is happening for mc
>>
>> I think that such behavior is clearly wrong. But it's a long term
>> issue. So maybe I'm wrong and this is a correct behavior?
>
> The daemons are doing reverse DNS lookups on the IP addresses and not
> getting any answers.
>
> You can either tweak that in the resolv.conf file so it doesn't take
> so long to give up (see the man page for options) or configure your
> services to ignore it.

I added
options timeout:5 attempts:1 no-check-names
and it doesn't solve problems. I still can't use samba, mc, sudo.

>
> For sshd you just need to uncomment the following line in sshd.conf:
>
> #UseDns no

Thanks, that's done the trick.

>
>  But I don't see anything wrong with how things are happening in this situation.

Some programs like apache, postgresql, mysql doesn't have any problems
with dns - it's great :) But some programs doesn't want to run without
dns - sudo, samba, mc (and probably many, many other) - from my point
of view this is a big problem.

Regards,
Michal