Vanilla kernel >=2.4.28-rc2 incompatibility with ADSL modem Dlink DSL-G300+

Vanilla kernel >=2.4.28-rc2 incompatibility with ADSL modem Dlink DSL-G300+

[Alessandro Selli]

  Hello,
I found a problem having to to with the plain vanilla 2.4.28-rc2 and 
2.4.29 kernels when I try to use a Dlink DSL-300G+ ethernet ADSL modem 
on a SS5 machine.

The domain "route-add.net" is running on a Sun SparcStation 5 machine, 
equipped with a Micro-SPARCII, 85 MHz processor. This machine has beeing 
running the domain (web, smtp, ssh, imap, telnet, gopher, finger, 
auth/ident, dns) for a year. The machine has two "le" (10 base T) 
ethernet ports, one is connected to the ADSL modem, the other to the LAN.
The OS is Debian stable (Woody, 3.0).
The kernel is a plain vanilla one, downloaded from 
ftp.it.kernel.org/pub/linux/kernel/v2.4 with no patches applied to it.

The problem showed up after updating to kernel 2.4.28: the ADSL 
connection would never outlive the fifteenth minute.  Even though the 
modem still sensed the ADSL carrier and could be reached into its 
web-based internal control panel over the same ethernet connection that 
served the data exchanged with the ISP, after fifteen minutes it could 
first reach the ISP gateway the connection failed and no packets could 
be neither sent nor received with any host outside the LAN.  The 
connection would be available again after a period varying from a few 
minutes to several hours, three quarters of an hour on the average.
A script that was let running from Jannuary 18th to February 3rd (data 
from Jannuary 29th was lost) produced the following data:

http://route-add.net/ping-noping.txt ("riuscito" = success, "fallito" = 
failed)
http://route-add.net/ping-noping_18012005-28012005.txt
http://route-add.net/ping-noping_07012005-17012005.txt ("persa" = lost 
[connection], "tornata" = [coonection is] back)

I tried changing the wiring, I swapped the ethernet ports the LAN and 
ADSL modem where connected to, I swapped the modem with an identical one 
from a colleague of mine, I upgraded to kernel 2.4.29 all to no avail.
   I then tried the 2.4.28-rc{1,2,3} kernels, and I found the 2.4.28-rc1 
not to exhibit the problem, that manifests itself on the 2.4.28-rc{2,3} 
kernels.
   The problem is sparc-specific, a PC with the very same configuration 
(Debian stable, plain vanilla kernels etc.) did not suffer any 
connection drops.

-- 
Alessandro Selli
Tel: 340.839.73.05
http://alessandro.route-add.net

Vanilla kernel >=2.4.28-rc2 incompatibility with ADSL modem Dlink DSL-G300+

[Alessandro Selli]

  Hello,
I found a problem having to to with the plain vanilla 2.4.28-rc{2,3} and
2.4.29 kernels when I try to use a Dlink DSL-300G+ ethernet ADSL modem
on a SS5 machine.

The domain "route-add.net" is running on a Sun SparcStation 5 machine,
equipped with a Micro-SPARCII, 85 MHz processor. This machine has beeing
running the domain (web, smtp, ssh, imap, telnet, gopher, finger,
auth/ident, dns) for a year. The machine has two "le" (10 base T)
ethernet ports, one is connected to the ADSL modem, the other to the LAN.
The OS is Debian stable (Woody, 3.0).
The kernel is a plain vanilla one, downloaded from
ftp.it.kernel.org/pub/linux/kernel/v2.4 with no patches applied to it.

The problem showed up after updating to kernel 2.4.28: the ADSL
connection would never outlive the fifteenth minute.  Even though the
modem still sensed the ADSL carrier and could be reached into its
web-based internal control panel over the same ethernet connection that
served the data exchanged with the ISP, after fifteen minutes it could
first reach the ISP gateway the connection failed and no packets could
be neither sent nor received with any host outside the LAN.  The
connection would be available again after a period varying from a few
minutes to several hours, three quarters of an hour on the average.
A script that was let running from Jannuary 18th to February 3rd (data
from Jannuary 29th was lost) produced the following data:

http://route-add.net/ping-noping.txt ("riuscito" = success, "fallito" =
failed)
http://route-add.net/ping-noping_18012005-28012005.txt
http://route-add.net/ping-noping_07012005-17012005.txt ("persa" = lost
[connection], "tornata" = [coonection is] back)

I tried changing the wiring, I swapped the ethernet ports the LAN and
ADSL modem where connected to, I swapped the modem with an identical one
from a colleague of mine, I upgraded to kernel 2.4.29 all to no avail.
   I then tried the 2.4.28-rc{1,2,3} kernels, and I found the 2.4.28-rc1
not to exhibit the problem, that manifests itself on the 2.4.28-rc{2,3}
kernels.
   The problem is sparc-specific, a PC with the very same configuration
(Debian stable, plain vanilla kernels etc.) did not suffer any
connection drops.

-- 
Alessandro Selli
Tel: 340.839.73.05
http://alessandro.route-add.net

Re: Vanilla kernel >=2.4.28-rc2 incompatibility with ADSL modem Dlink DSL-G300+

[Pedro Larroy]

On Sun, Mar 06, 2005 at 06:35:28PM +0100, Alessandro Selli wrote:
>  Hello,
> I found a problem having to to with the plain vanilla 2.4.28-rc{2,3} and
> 2.4.29 kernels when I try to use a Dlink DSL-300G+ ethernet ADSL modem
> on a SS5 machine.
> 
> The domain "route-add.net" is running on a Sun SparcStation 5 machine,
> equipped with a Micro-SPARCII, 85 MHz processor. This machine has beeing
> running the domain (web, smtp, ssh, imap, telnet, gopher, finger,
> auth/ident, dns) for a year. The machine has two "le" (10 base T)
> ethernet ports, one is connected to the ADSL modem, the other to the LAN.
> The OS is Debian stable (Woody, 3.0).
> The kernel is a plain vanilla one, downloaded from
> ftp.it.kernel.org/pub/linux/kernel/v2.4 with no patches applied to it.
> 
> The problem showed up after updating to kernel 2.4.28: the ADSL
> connection would never outlive the fifteenth minute.  Even though the
> modem still sensed the ADSL carrier and could be reached into its
> web-based internal control panel over the same ethernet connection that
> served the data exchanged with the ISP, after fifteen minutes it could
> first reach the ISP gateway the connection failed and no packets could
> be neither sent nor received with any host outside the LAN.  The
> connection would be available again after a period varying from a few
> minutes to several hours, three quarters of an hour on the average.
> A script that was let running from Jannuary 18th to February 3rd (data
> from Jannuary 29th was lost) produced the following data:
> 
> http://route-add.net/ping-noping.txt ("riuscito" = success, "fallito" =
> failed)
> http://route-add.net/ping-noping_18012005-28012005.txt
> http://route-add.net/ping-noping_07012005-17012005.txt ("persa" = lost
> [connection], "tornata" = [coonection is] back)
> 
> I tried changing the wiring, I swapped the ethernet ports the LAN and
> ADSL modem where connected to, I swapped the modem with an identical one
> from a colleague of mine, I upgraded to kernel 2.4.29 all to no avail.
>   I then tried the 2.4.28-rc{1,2,3} kernels, and I found the 2.4.28-rc1
> not to exhibit the problem, that manifests itself on the 2.4.28-rc{2,3}
> kernels.
>   The problem is sparc-specific, a PC with the very same configuration
> (Debian stable, plain vanilla kernels etc.) did not suffer any
> connection drops.
> 
> -- 
> Alessandro Selli
> Tel: 340.839.73.05
> http://alessandro.route-add.net
> 
> -
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I have seen similar problems due to high sequence numbers on the tcp
packets on some adsl routers. Took a while to discover that since the
connection misteriously ceased to work from some boxes after some time
transmitting data ok. Looks like some manufacturers such as efficient
networks adsl routers, doesn't follow the standards.

I'd suggest running tcpdump and doing some observation.

-- 
Pedro Larroy Tovar | Linux & Network consultant |  pedro%larroy.com 
Make debian mirrors with debian-multimirror: http://pedro.larroy.com/deb_mm/
	* Las patentes de programación son nocivas para la innovación * 
				http://proinnova.hispalinux.es/

Re: Vanilla kernel >=2.4.28-rc2 incompatibility with ADSL modem Dlink DSL-G300+

[Alessandro Selli]

Pedro Larroy wrote:

[....]

>>I tried changing the wiring, I swapped the ethernet ports the LAN and
>>ADSL modem where connected to, I swapped the modem with an identical one
>>from a colleague of mine, I upgraded to kernel 2.4.29 all to no avail.
>>  I then tried the 2.4.28-rc{1,2,3} kernels, and I found the 2.4.28-rc1
>>not to exhibit the problem, that manifests itself on the 2.4.28-rc{2,3}
>>kernels.
>>  The problem is sparc-specific, a PC with the very same configuration
>>(Debian stable, plain vanilla kernels etc.) did not suffer any
>>connection drops.

   I forgot to mention: as I was suggested to do by other people, I 
changed the settings of the two parameters:

/proc/sys/net/ipv4/tcp_ecn
/proc/sys/net/ipv4/tcp_default_win_scale

   This did not help, though.

> I have seen similar problems due to high sequence numbers on the tcp
> packets on some adsl routers. Took a while to discover that since the
> connection misteriously ceased to work from some boxes after some time
> transmitting data ok. Looks like some manufacturers such as efficient
> networks adsl routers, doesn't follow the standards.
>
> I'd suggest running tcpdump and doing some observation.

   Thank you for your reply, I'll do as you suggested.

-- 
Alessandro Selli
Tel: 340.839.73.05
http://alessandro.route-add.net