Re (n): finding the ip address for dns, nslookup & etc.
On Tue, Aug 10, 2010 at 04:18:25PM -0700, peasthope@shaw.ca wrote:
> From: Tom H <tomh0665@gmail.com.>
> Date: Mon, 9 Aug 2010 13:16:42 -0400
> > Why did you install it[dnsmasq]?
>
> * Local name resolution is more efficient than having
> each local machine query the ISP nameserver.
> * The ISP can change the IP address of a nameserver at will.
> My dnsmasq system will get a new address by dhcp and
> consequently name resolution in my LAN will continue.
> If a machine on my LAN relies on a static address for
> an ISP namerserver, resolution will fail when the
> address of the nameserver changes.
>
> > [pi.shawcable.net] It's your ISP's search domain.
>
> OK, but if a system has an address for a working nameserver,
> what is the value or significance of the search domain?
>
> From: Jaime Di Cristina <jaime.dc@gmail.com>
> Date: Mon, 9 Aug 2010 12:44:50 -0400
> > /etc/resolv.conf points to the localhost so that other programs are
> > directed to the dnsmasq cache instead of going directly to your real
> > DNS servers. Since dnsmasq takes care of sending queries to upstream
> > servers there is no need for other programs to be aware of those
> > servers.
>
> That all makes perfect sense; but why does dnsmasq keep upstream
> addresses in /var/run/dnsmasq/resolv.conf rather than in
> /etc/dnsmasq/resolv.conf? I don't see anything in Debian policy
> dictating use of /var/run/.
I'm not well versed in Debian Policy. But I'll venture to guess that
the file in question does not belong in /etc because it is not meant
to store permanent configuration information. At least for the case
where you get the nameservers via dhcp.
> One last point: my Linux router might not need resolvconf.
> This is from http://en.wikipedia.org/wiki/Resolvconf
> "The resolvconf program is only necessary when a system has
> multiple programs that need to dynamically modify the nameserver
> information. In a simple system where the nameservers do not
> change often or are only changed by one program, the resolv.conf
> configuration file is adequate."
No, you do not need it. DHCP will keep you pointing in the right
direction.
> Thanks for the help, ... Peter E.
You're welcome.
--
Jaime
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