ADSL problems

This is rather long, but I don't know what info is needed to determine
what the problem is.

I have
One computer with Debian testing/unstable
Kernel 2.4.20 (rather custom)
1 built-in ethernet card (SiS900 in K7S5A)
External Speedstream 5100 ADSL modem
1 static IP
dhclient 2.0pl5

The ISP uses DHCP and when I set Win98 (dualboot) up for ADSL I barely
need to do anything else than tell it to use DHCP; there are no domains,
IPs, DNS servers or logins/passwords to enter in the network config and
it just works (the ISP also doesn't need to know the card's MAC address).
I can't tell which IP I get assigned that way, but I'm fairly certain
it's the right one (i.e. the static one).

So it seems like it's as simple as it can be, but I can't get it to work
in Linux. I've never done anything with ethernet before, so perhaps that's
the problem, but I can't find any docs or howtos that tell me what the
problem is either (but then, I don't know what it is I need to know).

I have

auto eth0
iface eth0 inet dhcp

in /etc/network/interfaces, so eth0 is set up on boot:
Aug 22 12:02:11 vampire dhclient: Listening on LPF/eth0/00:07:95:32:2c:cc
Aug 22 12:02:11 vampire dhclient: Sending on LPF/eth0/00:07:95:32:2c:cc
Aug 22 12:02:11 vampire dhclient: Sending on Socket/fallback/fallback-net
Aug 22 12:02:11 vampire dhclient: DHCPREQUEST on eth0 to 255.255.255.255 port 67
Aug 22 12:02:12 vampire kernel: eth0: Media Link On 100mbps full-duplex
Aug 22 12:02:14 vampire dhclient: DHCPREQUEST on eth0 to 255.255.255.255 port 67
Aug 22 12:02:14 vampire dhclient: DHCPACK from 129.142.192.1
Aug 22 12:02:14 vampire dhclient: bound to <static IP> -- renewal in 900 seconds.
(sometimes there apparently are some lags or something so it can be delayed
or fail).

The dhclient config file is empty, so far, but judging from
/var/lib/dhcp/dhclient.leases, it determines the right info
automatically (or what I assume is the right info, anyway; my
ISP has gotten so 'user-friendly' lately that there is no
technical info to be found anywhere).

# ifconfig eth0
eth0 Link encap:Ethernet HWaddr 00:07:95:32:2C:CC
inet addr:<static IP> Bcast:129.142.207.255 Mask:255.255.240.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:11 errors:0 dropped:0 overruns:0 frame:0
TX packets:3 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:1260 (1.2 Kb) TX bytes:1026 (1.0 Kb)
Interrupt:11 Base address:0xd800

# netstat -rn
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
192.168.1.0 0.0.0.0 255.255.255.0 U 40 0 0 dummy0
129.142.192.0 0.0.0.0 255.255.240.0 U 40 0 0 eth0
0.0.0.0 129.142.192.1 0.0.0.0 UG 40 0 0 eth0
(I'm not quite certain what dummy0 is or if I need it. I think it was
added automatically when I installed Debian (on a box without ethernet)).

With this, I get incoming port probes from all over the world, but I can't
get out; all outgoing traffic fails immediately (i.e. it doesn't time out,
but fails instantly):
Aug 22 13:19:37 vampire fetchmail[670]: couldn't find canonical DNS name of
wien.get2net.dk
Aug 22 13:19:37 vampire fetchmail[670]: Query status=11 (DNS)

Pings to IP addresses also don't work (so it probably isn't merely a DNS
problem).
And I can't connect to the modem's IP either (the one used for configuration).
None of these attempts cause any traffic on my eth0 monitor (while the
incoming probes do).
I do have iptables set up (for dial-up ppp), but it doesn't block any of
this traffic (yet), so that's not the problem.

Can anybody see what I'm doing wrong?


-R.

ras2 wrote:

> Speedstream 5100

I don't recognize 5100. Could it possibly be the Thompson (Alcatel) 510?

In any event if you are using DHCP in windows and have already set up the
modem to work under linux, you don't need to again set it up to work under
linux.
Instead, all you have to do is to set your linux system to use a lan
connection with dhcp.

The modem has a built0in router so all computers connected to it, either
directly or through a hub or switch, are simply configured as if they are
part of a LAN using a private ip range and getting their private ip
addresses from the router using dhcp.

On 2003-08-22 12:09:17 GMT, Clive Dove <(E-Mail Removed)>
wrote in <NJn1b.266628$(E-Mail Removed) .rogers.com>:
> ras2 wrote:
>
>> Speedstream 5100
>
> I don't recognize 5100. Could it possibly be the Thompson (Alcatel) 510?

No, it's from Siemens/Efficient Networks. I think it may be a cut-down
version of the 5200 (no USB option).

> In any event if you are using DHCP in windows and have already set up the
> modem to work under linux, you don't need to again set it up to work under
> linux.

The modem was set up by the provider. I assume that's how they can
avoid any kind of authentication info from the users.

> Instead, all you have to do is to set your linux system to use a lan
> connection with dhcp.

mh. but isn't that what I'm doing when I have
auto eth0
iface eth0 inet dhcp
in /etc/network/interfaces?

# route
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
129.142.192.0 * 255.255.240.0 U 0 0 0 eth0
default 129.142.192.1 0.0.0.0 UG 0 0 0 eth0
(129.142.192.1 is the 'routers' address dhclient lists after it's run).

The only thing I wonder about with this is that when I use dial-up,
I get something like this:

# route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
195.82.196.208 0.0.0.0 255.255.255.255 UH 0 0 0 ppp0
0.0.0.0 195.82.196.208 0.0.0.0 UG 0 0 0 ppp0

Is it possible that dhclient should be setting up 129.142.192.0 as host
(the H flag), but doesn't for some reason?

> The modem has a built0in router so all computers connected to it, either
> directly or through a hub or switch, are simply configured as if they are
> part of a LAN using a private ip range and getting their private ip
> addresses from the router using dhcp.

I think the 'simply' bit is what I'm missing...


-R.

ras2 wrote:

> On 2003-08-22 12:09:17 GMT, Clive Dove <(E-Mail Removed)>
> wrote in <NJn1b.266628$(E-Mail Removed) .rogers.com>:
>> ras2 wrote:
>>
>>> Speedstream 5100
>>
>> I don't recognize 5100. Could it possibly be the Thompson (Alcatel) 510?
>
> No, it's from Siemens/Efficient Networks. I think it may be a cut-down
> version of the 5200 (no USB option).
>
>> In any event if you are using DHCP in windows and have already set up the
>> modem to work under linux, you don't need to again set it up to work
>> under linux.
>
> The modem was set up by the provider. I assume that's how they can
> avoid any kind of authentication info from the users.
>
>> Instead, all you have to do is to set your linux system to use a lan
>> connection with dhcp.
>
> mh. but isn't that what I'm doing when I have
> auto eth0
> iface eth0 inet dhcp
> in /etc/network/interfaces?
>
> # route
> Kernel IP routing table
> Destination Gateway Genmask Flags Metric Ref Use
> Iface
> 129.142.192.0 * 255.255.240.0 U 0 0 0
> eth0
> default 129.142.192.1 0.0.0.0 UG 0 0 0
> eth0 (129.142.192.1 is the 'routers' address dhclient lists after it's
> run).
>
> The only thing I wonder about with this is that when I use dial-up,
> I get something like this:
>
> # route -n
> Kernel IP routing table
> Destination Gateway Genmask Flags Metric Ref Use
> Iface
> 195.82.196.208 0.0.0.0 255.255.255.255 UH 0 0 0
> ppp0
> 0.0.0.0 195.82.196.208 0.0.0.0 UG 0 0 0
> ppp0
>
> Is it possible that dhclient should be setting up 129.142.192.0 as host
> (the H flag), but doesn't for some reason?
>
>> The modem has a built0in router so all computers connected to it, either
>> directly or through a hub or switch, are simply configured as if they are
>> part of a LAN using a private ip range and getting their private ip
>> addresses from the router using dhcp.
>
> I think the 'simply' bit is what I'm missing...
>
>
> -R.


Without access to an online manual, I have difficulty knowing what your
device is.
With home dsl devices, the computer generally connects to the dsl modem
directly or through a router, either one that is built into the modem or
one that is separate from the modem and between the modem and the computer.

The most common ethernet dsl modems use a built-in router which has its own
dhcp daemon, in which case, the computer is talking to a router, not the
modem and it simply uses standard a lan connection with dhcp. In such
cases, the ip address and gateway ip address seen in the routing table is
in a private ip range, usually 192.168.1.x or 192.168.0.x.

If the modem has no router, then the computer has to have a PPPoE or PPPoA
client. This might be something like Roaring Penguin PPPoE (rp-pppoe) used
with those services that use PPPoE.

We seem to be mixing apples and oranges. I was talking about straight lan
with dhcp which (unless the service was a cable service) would imply the
presence of a router that performs ip masquerading (Network Address
Translation) in which case the routing table would be given a private ip
address by the dhcp daemon.

But your routing table is showing a public ip address. which implies either
that you have plugged in the address or that the dhcp daemon that is
supplying it is in a public network. As dhcp broadcasts are not routable,
this implies the absence of a router.
As you are using dsl service, not cable service, this implies that you need
client software that runs in linux.

That the ip address seen through your dial-up modem is different than the
one seen through your ethernet card is just what I would expect. Your
provider is running different serves using different ip ranges.

(To be clear and at the risk of over-simplifying, cable service is the
service that runs off your television cable connection. DSL service uses
upper frequencies on your telephone line, and dial-up uses the ordinary
frequencies used by your telephone)

I am hoping that someone who is using a Siemen/Efficient Networks dsl modem
will jump in here.

On 2003-08-23 13:20:35 GMT, Clive Dove <(E-Mail Removed)>
wrote in <DSJ1b.242929$(E-Mail Removed). rogers.com>:

> Without access to an online manual, I have difficulty knowing what your
> device is.

It's not easy to find one, partly because the Efficient Networks site
is rather lacking in info and partly because the 5100 can apparently
be upgraded through software somehow, so there are at least three
versions of it. And the Efficient pictures of what is allegedly a
5100 don't look much like the one I have.

This appears to be the only available manual and it seems to cover most of
the 5000 range:
http://www.tnics.com/5200_Router_Manual.pdf

> The most common ethernet dsl modems use a built-in router which has its own
> dhcp daemon, in which case, the computer is talking to a router, not the
> modem and it simply uses standard a lan connection with dhcp.

It must be one of those.

> In such cases, the ip address and gateway ip address seen in the routing
> table is in a private ip range, usually 192.168.1.x or 192.168.0.x.

Not always, it seems.

> We seem to be mixing apples and oranges.

I think it's just that my (or my ISP's) system behaves in an unusual
manner.

> I was talking about straight lan with dhcp which (unless the service was
> a cable service) would imply the presence of a router that performs ip
> masquerading (Network Address Translation) in which case the routing table
> would be given a private ip address by the dhcp daemon.
>
> But your routing table is showing a public ip address. which implies either
> that you have plugged in the address or that the dhcp daemon that is
> supplying it is in a public network.

It's supplied.

> As dhcp broadcasts are not routable, this implies the absence of a router.
> As you are using dsl service, not cable service, this implies that you need
> client software that runs in linux.

Well... I am now, finally, online with ADSL (using dhcpcd) and the routing
table still looks like this:

# netstat -rn
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
129.142.192.0 0.0.0.0 255.255.240.0 U 40 0 0 eth0
0.0.0.0 129.142.192.1 0.0.0.0 UG 40 0 0 eth0

> That the ip address seen through your dial-up modem is different than the
> one seen through your ethernet card is just what I would expect. Your
> provider is running different serves using different ip ranges.

Right. That was just because I wondered why the host flag was missing
when eth0 was up, but present when I was online via dial-up.

Anyway, I am officially a moron. I haven't figured out how it happened,
but it turned out that iptables was doing something that kept the ADSL
from working (which explains how there could be incoming traffic, but
no outgoing, at least). I need to look at my rules, it seems (they
really only should have covered ppp0).


-R.

On 2003-08-23 21:38:13 GMT, Clive Dove <(E-Mail Removed)>
wrote in <99R1b.255459$(E-Mail Removed). rogers.com>:
>
> Do you happen to know if there is an online user's guide for this device or
> one in the same model range?

I haven't found any, so the PDF I posted the link for is probably
your best bet.

There isn't much to find about the 5100 at all, so I wonder if it's
new.


-R.

ras2 wrote:

> On 2003-08-23 21:38:13 GMT, Clive Dove <(E-Mail Removed)>
> wrote in <99R1b.255459$(E-Mail Removed). rogers.com>:
>>
>> Do you happen to know if there is an online user's guide for this device
>> or one in the same model range?
>
> I haven't found any, so the PDF I posted the link for is probably
> your best bet.
>
> There isn't much to find about the 5100 at all, so I wonder if it's
> new.
>
>
> -R.

Probably.

I could not find it in the Siemens site.