DSL battling rojter - help!
 

My internet connection is through a Siemens Speedstream 4100 DSL modem
connected to AT&T (sbcglobal.net), and a Dlink WBR-2310 router.

Late last night, I changed the administrative password on the router,
and for some reason it didn't take right, so I had to reset the router
to get the password cleared. Unfortunately, this also lost all my
connection settings to the DSL, and I lost the internet for a while.

After some effort and a couple of phone calls to AT&T technical
support, I determined the following:

1. If I connect my CentOS (main) box to the DSL modem, I can log into
the modem and check all the settings, and I can ping sites on the web
from there, but I can't actually get any web pages to load. This is
using Firefox 3.6.4 (the L&G).

2. If I connect a WinXP box to the modem, it gets to the web without
any trouble.

3. If I connect the router to the modem and run the machines through
the router, no one gets to the web. I managed to get it to a point
where I could acquire an IP address, but nothing on the web was
visible.

I'll figure out the router problem one way or another, but it really
concerns me that I couldn't get to the web from my CentOS box at all.

Before the router password fiasco, everything was working absolutely
perfectly, and I did not change ANY settings on my machines.

Now, I do have a line in /etc/hosts that sets my machine id, and its
IP address to 192.168.0.100, which is what it normally should be for
access through the router as it is the primary machine on it. (I need
that because my VMWare SMB is set up to use that for connections
between my virtual XP machine and my CentOS host.) Could that be the
problem with internet access directly through the DSL modem? If so,
how do I change this to ensure that the hostname is set properly but
the IP address matches whatever the DSL modem gives back? How do I
then also ensure that the hostname and address are set right so my
host-VMWare samba connection still work?

Otherwise, what?

Thanks.

Mark
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DSL battling rojter - help!
 

On Sun, 2010-07-18 at 01:26 -0700, Mark wrote:
> 1. If I connect my CentOS (main) box to the DSL modem, I can log into
> the modem and check all the settings, and I can ping sites on the web
> from there, but I can't actually get any web pages to load. This is
> using Firefox 3.6.4 (the L&G).

No proper default gateway or dns server aettings. Of which some dsl
modems under linux you have to hard code those settings on the machine.
If your using dhcp and then go to make changes make sure to use
"dhclient" from the cmd line.

> 2. If I connect a WinXP box to the modem, it gets to the web without
> any trouble.

Yea winblows does a great job at this.

> 3. If I connect the router to the modem and run the machines through
> the router, no one gets to the web. I managed to get it to a point
> where I could acquire an IP address, but nothing on the web was
> visible.

Right, because the DSL Router is not in Bridged Mode. Enable Bridged
mode on the Siemens Modem.

> I'll figure out the router problem one way or another, but it really
> concerns me that I couldn't get to the web from my CentOS box at all.

See above.

> Before the router password fiasco, everything was working absolutely
> perfectly, and I did not change ANY settings on my machines.
>
> Now, I do have a line in /etc/hosts that sets my machine id, and its
> IP address to 192.168.0.100, which is what it normally should be for
> access through the router as it is the primary machine on it. (I need
> that because my VMWare SMB is set up to use that for connections
> between my virtual XP machine and my CentOS host.) Could that be the
> problem with internet access directly through the DSL modem? If so,
> how do I change this to ensure that the hostname is set properly but
> the IP address matches whatever the DSL modem gives back? How do I
> then also ensure that the hostname and address are set right so my
> host-VMWare samba connection still work?

Your confusing here either you want to configure the machine for dhcp or
static addys. Get the first part working then decide what you need.
"hostname foobar" from the command line.
127.0.0.1 foobar localhost.localdomain localhost #
example

John

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DSL battling rojter - help!
 

Sorry about the "j" - dvorak artifact....

Okay, let me try again.

First, here's my (new) /etc/hosts file:

# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1 mhrichter localhost localhost.localdomain
#192.168.0.100 mhrichter mhrichter.adsl.irvine.sbcglobal.net
::1 localhost6.localdomain6 localhost6

If I run ifup eth0, here's what I get:

eth0 Link encap:Ethernet HWaddr 00:1E:90:F3:D2:8D
inet addr:192.168.0.100 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::21e:90ff:fef3:d28d/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:5557646 errors:4 dropped:0 overruns:0 frame:4
TX packets:3497153 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:7118384647 (6.6 GiB) TX bytes:413380509 (394.2 MiB)
Interrupt:153 Base address:0xc000

With this setup, I can login to the DSL modem, which shows the
following configuration:

DSL UP
Connection UP
User ID xxxxxxx@sbcglobal.net
Connected at 1536 Kbps (downstream)
384 Kbps (upstream)
IP Address 69.234.16.38
IP Gateway 69.234.31.254
DNS Servers 68.94.156.1 dnsr1.sbcglobal.net
68.94.157.1 dnsr2.sbcglobal.net
Mode PPP on the modem (Public IP for LAN device)
Timeout Never
Modem Information
Modem Name SpeedStream
Model 4100
Serial Number 20013A3E0A514
Software Version1.0.0.53
MAC Address 00:13:A3:E0:A5:14
First Use Date 2006/10/31 00:38:02 GMT
Local Network
Modem IP Address 192.168.0.1
Ethernet Status Connected

In this shape, I can ping, say, google.com from the modem and get a response.

But, when I run dhclient, I get this:

# dhclient
Internet Systems Consortium DHCP Client V3.0.5-RedHat
Copyright 2004-2006 Internet Systems Consortium.
All rights reserved.
For info, please visit http://www.isc.org/sw/dhcp/

/sbin/dhclient-script: configuration for vmnet8 not found. Continuing
with defaults.
/etc/sysconfig/network-scripts/network-functions: line 78: vmnet8: No
such file or directory
Listening on LPF/vmnet8/00:50:56:c0:00:08
Sending on LPF/vmnet8/00:50:56:c0:00:08
Listening on LPF/eth0/00:1e:90:f3:d2:8d
Sending on LPF/eth0/00:1e:90:f3:d2:8d
Sending on Socket/fallback
DHCPREQUEST on vmnet8 to 255.255.255.255 port 67
DHCPREQUEST on eth0 to 255.255.255.255 port 67
DHCPACK from 192.168.0.1
bound to 69.234.16.38 -- renewal in 291 seconds.

And after that I can't reach the modem or the internet. If I run
ifdown eth0 and then ifup eth0, I get the 192.168.0.100 IP address
back, and I can reach the modem, but not the internet.

(So I'm back on the Windows machine to send this.)

This probably seems pretty basic to many of you, but I'm still a
neophyte at the details of IP under Linux. IOW, I'm lost. None of
this was any kind of problem before I reset/mangled the router.

One other question: I notice that the router claims to be 192.168.0.1,
but so does the modem. Could that be part of the problem, i.e.,
should I change the router's IP address to something else? I remember
it was 192.168.0.2 before the fiasco....

Thanks again.
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DSL battling rojter - help!
 

On Sun, Jul 18, 2010 at 07:58:02AM -0700, Mark wrote:
> And after that I can't reach the modem or the internet. If I run
> ifdown eth0 and then ifup eth0, I get the 192.168.0.100 IP address
> back, and I can reach the modem, but not the internet.

What do you see with "ip ro ls"? Is there a default route?

Whit
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DSL battling rojter - help!
 

On Sun, 2010-07-18 at 07:58 -0700, Mark wrote:

> And after that I can't reach the modem or the internet. If I run
> ifdown eth0 and then ifup eth0, I get the 192.168.0.100 IP address
> back, and I can reach the modem, but not the internet.

Ok you getting a dhcp addy here? Look at "system-config-network" your
not getting a proper gateway or dns entry. You will have to probaly
define it manually as I've come to find out with many cheap routers or
either this is a bug in linux. Use "route" to check for the DFG.


> One other question: I notice that the router claims to be 192.168.0.1,
> but so does the modem. Could that be part of the problem, i.e.,
> should I change the router's IP address to something else? I remember
> it was 192.168.0.2 before the fiasco....

If you Bridge the DSL to function as a Modem Only it does not matter
that goes out the window. It's no concern when your in Routing Mode
with the other. But you can not have two same ips defined as your
seeing so the bridge needs one for management and the router a different
one. So one has to be changed.

John


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DSL battling rojter - help!
 

realistically you are not getting any dns

when in dhcp mode, the /etc/resolv.conf file typically will point to the
router ip instead of real dns servers

once you deal with that, you should be ok...

thing is, if you stay in dhcp mode, the next time you dhcp or reboot, the
resolv.conf will go back to pointing at the router ip to get dns

so, as others mentioned, if you disable dhcp mode and hard code your ip,
netmask, gateway, and resolv.conf file among other things, you will be ok

- rh

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DSL battling rojter - help!
 

On Sun, Jul 18, 2010 at 8:18 AM, Whit Blauvelt <whit@transpect.com> wrote:
>
> What do you see with "ip ro ls"? Is there a default route?
>
Yes, but it's going to the router even when the router is not in the loop.

On Sun, Jul 18, 2010 at 8:23 AM, JohnS <jses27@gmail.com> wrote:
>
> Ok you getting a dhcp addy here? Look at "system-config-network" your
> not getting a proper gateway or dns entry. You will have to probaly
> define it manually as I've come to find out with many cheap routers or
> either this is a bug in linux. Use "route" to check for the DFG.
>
route shows 192.168.0.2 (the router) as the DFG.

In s-c-n, the gateways are 192.168.0.2 & 192.168.0.1, in that order.

> If you Bridge the DSL to function as a Modem Only it does not matter
> that goes out the window. It's no concern when your in Routing Mode
> with the other. But you can not have two same ips defined as your
> seeing so the bridge needs one for management and the router a different
> one. So one has to be changed.
>
According to AT&T, the modem has to be in PPP mode to work, and that
does work for XP

I changed the router to 192.168.0.2, but that has no effect when the
router is out of the loop. I still can't get out thru the modem hrom
CentOS, with or without the router.

Without the router, is the modem the DFG? If not, what is (or should be)?

On Sun, Jul 18, 2010 at 8:37 AM, R-Elists <lists07@abbacomm.net> wrote:
> realistically you are not getting any dns
>
> when in dhcp mode, the /etc/resolv.conf file typically will point to the
> router ip instead of real dns servers
>
I thought thot was working before....

> once you deal with that, you should be ok...
>
> thing is, if you stay in dhcp mode, the next time you dhcp or reboot, the
> resolv.conf will go back to pointing at the router ip to get dns
>
I expect it has, many times - wasn't a problem until now.

> so, as others mentioned, if you disable dhcp mode and hard code your ip,
> netmask, gateway, and resolv.conf file among other things, you will be ok
>
I was using a static IP with the router, but without it,...

Part of the problem is that these things come up so rarely I forget
the details in between, so how do I set the GW & netmask by hand?
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DSL battling rojter - help!
 

On Sun, Jul 18, 2010 at 09:34:06AM -0700, Mark wrote:

> > What do you see with "ip ro ls"? Is there a default route?
> >
> Yes, but it's going to the router even when the router is not in the loop.

Generally when someone asks "What do you see" in a computer context, the
right answer is to run the command and paste the results. We need, not your
interpretation of the data - which you know is confused, right? - but the
data itself.

Best,
Whit
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DSL battling rojter - help!
 

On 07/18/10 07:58 AM, Mark wrote:
> If I run ifup eth0, here's what I get:
>
> eth0 Link encap:Ethernet HWaddr 00:1E:90:F3:D2:8D
> inet addr:192.168.0.100 Bcast:192.168.0.255 Mask:255.255.255.0
>
The mask: 255.255.255.0 above looks right, but down below:

Local Network
> Modem IP Address 192.168.0.1
> Ethernet Status Connected
>
> In this shape, I can ping, say, google.com from the modem and get a response.
>
> But, when I run dhclient, I get this:
>
> # dhclient
> Internet Systems Consortium DHCP Client V3.0.5-RedHat
> Copyright 2004-2006 Internet Systems Consortium.
> All rights reserved.
> For info, please visit http://www.isc.org/sw/dhcp/
>
> /sbin/dhclient-script: configuration for vmnet8 not found. Continuing
> with defaults.
> /etc/sysconfig/network-scripts/network-functions: line 78: vmnet8: No
> such file or directory
> Listening on LPF/vmnet8/00:50:56:c0:00:08
> Sending on LPF/vmnet8/00:50:56:c0:00:08
> Listening on LPF/eth0/00:1e:90:f3:d2:8d
> Sending on LPF/eth0/00:1e:90:f3:d2:8d
> Sending on Socket/fallback
> DHCPREQUEST on vmnet8 to 255.255.255.255 port 67
> DHCPREQUEST on eth0 to 255.255.255.255 port 67
> DHCPACK from 192.168.0.1
> bound to 69.234.16.38 -- renewal in 291 seconds.
>
>
And on the above, the mask is: 255.255.255.255 I don't run dhclient or
anything so I'm not sure where the config file is, but I'd suggest that
in addition to what's already been suggested you probably want to change
the above to have a subnet mask matching what comes up under the ifup,
namely: 255.255.255.0

HTH.


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DSL battling rojter - help!
 

On Sun, 2010-07-18 at 09:34 -0700, Mark wrote:
> route shows 192.168.0.2 (the router) as the DFG.
>
> In s-c-n, the gateways are 192.168.0.2 & 192.168.0.1, in that order.

Aww take out the 192.168.0.1 and leave the 192.168.0.2 that is the
Siemens Modem. Your dhcp range starts @ 192.168.0.100

> > If you Bridge the DSL to function as a Modem Only it does not matter
> > that goes out the window. It's no concern when your in Routing Mode
> > with the other. But you can not have two same ips defined as your
> > seeing so the bridge needs one for management and the router a different
> > one. So one has to be changed.
> >
> According to AT&T, the modem has to be in PPP mode to work, and that
> does work for XP

Well appanently I dont think they know to much. Try PPoE Mode for
Bridging, I have the Manual to it. Would you like to have it? Send a
email to my inbox.

"Bridged mode – this means a manual connection must take place each time
you
want to connect to the internet, similar to a dial-up connection.
This is a better way to connect as it poses less of a security risk than
routed mode,
and is easier to change settings such as your ISP username/password."

In other words this is an old Gateway Modem.

John



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