Problems setting up DNS, gateway und subnetmask!

[Henk Koster]

On Wed, 28 Dec 2005 13:20:53 +0000, David Hart wrote:

> On Wed, Dec 28, 2005 at 11:47:31AM +0100, Henk Koster wrote:
>> On Wed, 28 Dec 2005 02:07:02 +0200, Tamer Higazi wrote:
>> 
>> > Hi!
>> > I have received from my ISP an IP, DNS, Subnetmask and the DNS 
>> > Serverentries to add to my ubuntu linux machine
>> 
>> Whoa! This is where you are wrong already -- these data are for your 
>> ADSL router; your Ubuntu Linux machine is on the inside 10.0.0.0/24 LAN.
> 
> You might well be right of course but, how do you know he's using an
> ADSL router?

Well, the 10.0.0.138 address for the gateway in the OP's message is a
give-away -- standard LAN address for Speedtouch ADSL router/modem...

> I was using an ADSL router/modem until a week ago which works as you
> describe (I've since lent it to a friend).  Right at this moment,
> while I'm reorganising my flat, I'm using my ADSL _modem_ plugged
> into my laptop's built-in eth0 interface which puts my real Internet
> address on that interface.  I'm routing the rest of my network to
> the Internet through the laptop's wireless interface on eth1.

<snip>
>> > auto eth0
>> > 
>> > iface eth0 inet static
>> > address 81.10.53.22
>> > netmask 255.255.255.252
>> > gateway 10.0.0.138
>> > dns-search lan
>> > dns-nameservers 163.121.128.134 212.103.160.18
>> 
>> This is a mix of LAN and Internet... no wonder it doesn't work.
>> I recommend you change it to 
>> 
>> auto eth0
>> iface eth0 inet dhcp
> 
> That's what I suggested and the simplest thing to try first.
>  
>> The router is also the nameserver for the LAN, so make sure that
>> /etc/resolv.conf reads as follows:
>> 
>> search lan
>> nameserver 10.0.0.138
> 
> That step will be unnecessary if they are assigned automatically by
> DHCP.

Sure... mea culpa

>> With these settings you have a route from your Linux machine to the LAN,
>> so next login with your browser to the router at http://10.0.0.138. You
>> must configure the router with the information given:
> [snip settings]
> 
> There's no must about it AFAICS.  The router/modem (if indeed, that is what
> it is) could very well pick its own settings up from DHCP.  That is what
> I would try first.

I only took the settings off my own Speedtouch ADSL router/modem because
I think they apply to the OP's case. 

> And don't you think it's a bit of an odd address for a router?  That's
> what makes me think it's not that but a typo.

Nothing odd about it IMHO. The router part has at interface eth0 a LAN
address (10.0.0.138); and real IP 81.10.53.22 at interface PPPoA, plus a
couple of nameservers, on the Internet side.

The OP could give my suggestions a try, chances are it'll work; and no
harm done if it doesn't.
 
Peace,

-- 
H.A.J. Koster
"Behavioral axioms are right, but agents make mistakes..."
(attributed to L.J. Savage)