2.6.27 seems to break something with DSL

2.6.27 seems to break something with DSL

[Philip Stark]

Hi,

I'm sorry, I didn't lurk before making my first posting to this list,
but it seemed to me that this might be an important problem/bug (if it
is one).

first off, my network infrastructure:

"internet" --(magic*)-- DSL Modem --(DHCP)-- Router --(DHCP)-- Computer
* PPPsomething i guess...

My observations so far:

with kernel =< 2.6.26 i can connect to the rest of the world perfectly
(ping works and i can browse "the internet")

now with kernel 2.6.27, i.e with all the release candidates and also
with the final version from yesterday i can ping anything just fine,
but i can't browse. that is when i 'wget kernel.org' it resolves the
address into the correct IP and then goes on to 'connecting' just to
grind to a complete halt. after some time of course it times out.
it seems to  be related to the packet  size because ping only seems to
work because it uses small packets. if i increase the ping size up to
1000 bytes, it fails as well. (while it does work on 2.6.26)

oh and it is the same problem on the wireless and the wired interface.
on 2 different laptops and on my desktop (which have different
networking chips, two intel and one realtek)

best Regards
Philip Stark

PS: if i horribly misposted, please slap me across the face and ignore me :)

Re: 2.6.27 seems to break something with DSL

[Marcin Slusarz]

On Sat, Oct 11, 2008 at 02:53:16PM +0200, Philip Stark wrote:
> Hi,
> 
> I'm sorry, I didn't lurk before making my first posting to this list,
> but it seemed to me that this might be an important problem/bug (if it
> is one).
> 
> first off, my network infrastructure:
> 
> "internet" --(magic*)-- DSL Modem --(DHCP)-- Router --(DHCP)-- Computer
> * PPPsomething i guess...
> 
> My observations so far:
> 
> with kernel =< 2.6.26 i can connect to the rest of the world perfectly
> (ping works and i can browse "the internet")
> 
> now with kernel 2.6.27, i.e with all the release candidates and also
> with the final version from yesterday i can ping anything just fine,
> but i can't browse. that is when i 'wget kernel.org' it resolves the
> address into the correct IP and then goes on to 'connecting' just to
> grind to a complete halt. after some time of course it times out.
> it seems to  be related to the packet  size because ping only seems to
> work because it uses small packets. if i increase the ping size up to
> 1000 bytes, it fails as well. (while it does work on 2.6.26)
> 
> oh and it is the same problem on the wireless and the wired interface.
> on 2 different laptops and on my desktop (which have different
> networking chips, two intel and one realtek)
> 
> best Regards
> Philip Stark
> 
> PS: if i horribly misposted, please slap me across the face and ignore me :)

CC'ing netdev

Re: 2.6.27 seems to break something with DSL

[Jarek Poplawski]

On 11-10-2008 16:02, Marcin Slusarz wrote:
> On Sat, Oct 11, 2008 at 02:53:16PM +0200, Philip Stark wrote:
>> Hi,
>>
>> I'm sorry, I didn't lurk before making my first posting to this list,
>> but it seemed to me that this might be an important problem/bug (if it
>> is one).
>>
>> first off, my network infrastructure:
>>
>> "internet" --(magic*)-- DSL Modem --(DHCP)-- Router --(DHCP)-- Computer
>> * PPPsomething i guess...
>>
>> My observations so far:
>>
>> with kernel =< 2.6.26 i can connect to the rest of the world perfectly
>> (ping works and i can browse "the internet")
>>
>> now with kernel 2.6.27, i.e with all the release candidates and also
>> with the final version from yesterday i can ping anything just fine,
>> but i can't browse. that is when i 'wget kernel.org' it resolves the
>> address into the correct IP and then goes on to 'connecting' just to
>> grind to a complete halt. after some time of course it times out.
>> it seems to  be related to the packet  size because ping only seems to
>> work because it uses small packets. if i increase the ping size up to
>> 1000 bytes, it fails as well. (while it does work on 2.6.26)
>>
>> oh and it is the same problem on the wireless and the wired interface.
>> on 2 different laptops and on my desktop (which have different
>> networking chips, two intel and one realtek)
>>
>> best Regards
>> Philip Stark
>>
>> PS: if i horribly misposted, please slap me across the face and ignore me :)

Hi,

Could you send tcpdump -v on some interface as near "internet" as
possible while doing this 1000 bytes ping? (Btw. what is this router?)
It would be nice to have this both for 2.6.26 and 2.6.27.

Thanks,
Jarek P.

Re: 2.6.27 seems to break something with DSL

[Grant Coady]

On Sat, 11 Oct 2008 14:53:16 +0200, "Philip Stark" <heller.barde@gmail.com> wrote:

>Hi,
>
>I'm sorry, I didn't lurk before making my first posting to this list,
>but it seemed to me that this might be an important problem/bug (if it
>is one).
>
>first off, my network infrastructure:
>
>"internet" --(magic*)-- DSL Modem --(DHCP)-- Router --(DHCP)-- Computer
>* PPPsomething i guess...

Well I connect via rp-pppoe to a bridged ADSL modem.  One recent gotcha 
is that iptables userspace has to be updated to match the latest kernel, 
how old is your distro?  What version iptables?  Last I checked 1.4.1.1 
was latest available from netfilter.org.

>but i can't browse. that is when i 'wget kernel.org' it resolves the
>address into the correct IP and then goes on to 'connecting' just to
>grind to a complete halt. after some time of course it times out.

This could be due to your firewall rules?  More people would have 
noticed if their networking died ;)  (Unless you're running a e1000, all 
bets off).

Grant.

Re: 2.6.27 seems to break something with DSL

[Patrick McHardy]

Grant Coady wrote:
> Well I connect via rp-pppoe to a bridged ADSL modem.  One recent gotcha 
> is that iptables userspace has to be updated to match the latest kernel, 
> how old is your distro?  What version iptables?  Last I checked 1.4.1.1 
> was latest available from netfilter.org.

No, old version should work fine, if not its a bug.

Re: 2.6.27 seems to break something with DSL

[Philip Stark]

2008/10/11 Grant Coady <grant_lkml@dodo.com.au>:
> On Sat, 11 Oct 2008 14:53:16 +0200, "Philip Stark" <heller.barde@gmail.com> wrote:
>>first off, my network infrastructure:
>>
>>"internet" --(magic*)-- DSL Modem --(DHCP)-- Router --(DHCP)-- Computer
>>* PPPsomething i guess...
>
> Well I connect via rp-pppoe to a bridged ADSL modem.

My modem deals with all the ppp stuff and just gives out plain
LAN/ethernet/however it is called.

One recent gotcha
> is that iptables userspace has to be updated to match the latest kernel,
> how old is your distro?  What version iptables?  Last I checked 1.4.1.1
> was latest available from netfilter.org.

iptables: 1.4.0
distro: archlinux (rolling release) with testing repo enabled

by the way, i forgot to mention that internet works fine anywhere else
and also i can connect to a http server _inside_ my network :)

>>but i can't browse. that is when i 'wget kernel.org' it resolves the
>>address into the correct IP and then goes on to 'connecting' just to
>>grind to a complete halt. after some time of course it times out.
>
> This could be due to your firewall rules?  More people would have
> noticed if their networking died ;)  (Unless you're running a e1000, all
> bets off).

actually one laptop is running a e1000e... but as said, its also with
wireless...

Philip Stark

Re: 2.6.27 seems to break something with DSL

[Luiz Fernando N. Capitulino]

Em Sat, 11 Oct 2008 14:53:16 +0200
"Philip Stark" <heller.barde@gmail.com> escreveu:

| I'm sorry, I didn't lurk before making my first posting to this list,
| but it seemed to me that this might be an important problem/bug (if it
| is one).
| 
| first off, my network infrastructure:
| 
| "internet" --(magic*)-- DSL Modem --(DHCP)-- Router --(DHCP)-- Computer
| * PPPsomething i guess...
| 
| My observations so far:
| 
| with kernel =< 2.6.26 i can connect to the rest of the world perfectly
| (ping works and i can browse "the internet")
| 
| now with kernel 2.6.27, i.e with all the release candidates and also
| with the final version from yesterday i can ping anything just fine,
| but i can't browse. that is when i 'wget kernel.org' it resolves the
| address into the correct IP and then goes on to 'connecting' just to
| grind to a complete halt. after some time of course it times out.
| it seems to  be related to the packet  size because ping only seems to
| work because it uses small packets. if i increase the ping size up to
| 1000 bytes, it fails as well. (while it does work on 2.6.26)

 If you haven't solved this issue yet you could try:

# echo 0 > /proc/sys/net/ipv4/tcp_timestamps

 We (Mandriva) have had some reports of this issue and it seems that
some broken routers can drop packages because of the timestamp (that's
what our local network guy has said). Disabling timestamps make it work
again.

-- 
Luiz Fernando N. Capitulino

Re: 2.6.27 seems to break something with DSL

[Philip Stark]

I was just going to say that Bug Nr. 11721 on bugzilla.kernel.org is
exactly my problem and is in fact resolved with the
solution/workaround presented there.

Thanks for your time
Philip Stark

2008/10/20 Luiz Fernando N. Capitulino <lcapitulino@mandriva.com.br>:
<snip>
> | it seems to  be related to the packet  size because ping only seems to
> | work because it uses small packets. if i increase the ping size up to
> | 1000 bytes, it fails as well. (while it does work on 2.6.26)
>
>  If you haven't solved this issue yet you could try:
>
> # echo 0 > /proc/sys/net/ipv4/tcp_timestamps
>
>  We (Mandriva) have had some reports of this issue and it seems that
> some broken routers can drop packages because of the timestamp (that's
> what our local network guy has said). Disabling timestamps make it work
> again.
>
> --
> Luiz Fernando N. Capitulino
>