Two elementary questions on LANs

[Timothy Murphy]

Ed Greshko wrote:

>> Just to be clear: dhcp wasn't running at the point I am talking about.
>> NM did delete the nameserver information in /etc/resolv.conf .
> 
> What precisely do you mean when you say "dhcp wasn't running at the
> point I am talking about"?
> 
> Do you mean your DHCP server was off?  Or, do you mean that you had
> BOOTPROTO=none set in your ifcfg- file?

I tried both.
DHCP was not running because the DHCPD server on my router
did not appear to be functioning, although dhcp was enabled.

> When you bring it down....NM will rewrite it to read....
> 
> # No nameservers found; try putting DNS servers into your
> # ifcfg files in /etc/sysconfig/network-scripts like so:
> #
> # DNS1=xxx.xxx.xxx.xxx
> # DNS2=xxx.xxx.xxx.xxx
> # DOMAIN=lab.foo.com bar.foo.com

NM certainly didn't write that in my ifcfg-wlan0
or I would have followed its advice.
IIRC, NM simply deleted the nameservers in /etc/resolv.conf 
that I had given.

I'm pretty sure I did add DNS1,DNS2 to ifcfg-wlan0 at one point
(I know I added them, but it could have been on another machine),
and it didn't seem to stop NM deleting the nameservers in /etc/resolv.conf .

My solution which seems to work is to go into NM's Manage Connections,
and give the IP address and nameservers there.

But I'd have to say that I can't see any point in NM deleting
the nameservers in /etc/resolv.conf .
I can't think of any circumstances in which one would be better off
with no nameservers listed.
It seems to me that the rational action for NM to take
would be to leave /etc/resolv.con as it is
if it cannot find any nameservers where it looks for them.



-- 
Timothy Murphy  
e-mail: gayleard /at/ eircom.net
tel: +353-86-2336090, +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland