Re: NM re-writing /etc/resolv.conf

[Timothy Murphy <gayleard eircom net>]

Dan Williams wrote:

> On Thu, 2012-03-01 at 12:46 +0000, Timothy Murphy wrote:
>> This morning, when I brought my hibernating Fedora-16 laptop to life,
>> I found NM had re-written /etc/resolv.conf , leaving only comments.
>> 
>> The laptop was connected to the internet before hibernation,
>> and had been working normally.
>> 
>> Why does NM do this?
>> Is there any way of stopping it?
> 
> If NM fails to find connectivity, then any nameservers
> in /etc/resolv.conf are no longer valid since they cannot be reached.
> If you have static nameservers that you'd like to use, those should be
> specified *per-connection*, since as David said, nameservers change
> depending on where the information came from (VPN, DHCP, PPP, etc).
> 
> Can you describe your problem in more detail?

The problem (I wouldn't call it a problem, more a nuisance)
is that when I hibernate, and then wake up my laptop,
I find that NM has deleted all the entries in /etc/resolv.conf
except for the comment lines.

Everything else seems to be working fine.
The laptop is connected to my LAN, and so to the internet.
I can browse to any site if I give the IP address.
It is just DNS that is not working.

My solution is to keep a copy of /etc/resolv.conf (in /common/tim/laptop/)
and just copy it back to /etc .
This takes a second.

As to the cause of the problem, I see
-----------------------------------
Mar  2 11:04:27 blanche NetworkManager[818]: get_secret_flags: assertion 
`is_secret_prop (setting, secret_name, error)' failed
Mar  2 11:04:27 blanche NetworkManager[818]: NetworkManager[818]: 
get_secret_flags: assertion `is_secret_prop (setting, secret_name, error)' 
failed
-----------------------------------
in /var/log/messages .
I assume this has something to do with it.

But my main point is that I cannot think of any circumstances
in which this action by NM could be of any help.
I can conceive that there might be situations
where it makes sense to replace the nameservers by others,
but I cannot think of any where it makes sense simply to delete them.

I'm not sure if this is relevant,
but I'm running dhcpd on my CentOS-6.2 server,
and this has the nameservers listed in /etc/dhcp/dhcpd.conf .






-- 
Timothy Murphy  
e-mail: gayleard /at/ eircom.net
tel: +353-86-2336090, +353-1-2842366
s-mail: School of Mathematics, Trinity College Dublin