network stall for kernel 2.2.19

network stall for kernel 2.2.19

[Ralf Hoffmann]

[-- Attachment #1: Type: text/plain, Size: 1900 bytes --]

Hi,

This is my first post to this list and I'm unsure if this is the right place
for my problem but I have read the FAQ and searched the archive without any
result.

At home I have a gateway-machine running kernel 2.2.19 which connects with ppp
to the internet and masq my main machine running kernel 2.4.12.
All the masq and forwarding stuff works great for most of the time.

But while connected I sometimes get a network stall at the gateway. I cannot
load any page, I always get a timeout. This only affects the gateway, not my
client machine. While the gateway can't open any connection, everything works at
my client!
After a half hour (or so) without any action from me everything goes back to
normal so also the gateway can make connections again.

I made some tcpdumps which I have attached:

The first "client-out1" is from "tcpdump -i ppp0" when running
"lynx www.boomerangsworld.de" at the client machine.
The page load is successful.

The second "server-out1" show the ouput of tcpdump when trying to load the same
page at the server.

The third "server-out2" is the ouput when everything is normal at the server.

I can't really read the tcpdump-output but what I notice is the missing "ack"!

I think the forwarding/masq works in this situation so the client isn't
affected, but something is wrong at the server.

My configuration:
Server:
  Pentium200MMX
  Slackware 7
  Kernel 2.2.19
Client:
  PIII 800
  Slackware 7 modified for Kernel 2.4
  Kernel 2.4.12

Please ask for more information, I don't know what's important and what's not.

Upgrade to Kernel 2.4 at the server isn't a choice.

Perhaps this has nothing to do with the kernel network code, but any help is
welcome, this problem is really annoying.

And again, if this is the wrong place for my problem, please excuse me.

Thanks in advance,

Ralf Hoffmann

P.S.: Please CC to me because I'm not subscribed to the list.


[-- Attachment #2: client-out1 --]
[-- Type: application/octet-stream, Size: 1490 bytes --]

22:53:56.301592 213.6.220.71.61037 > 212.227.220.93.www: S 643632369:643632369(0) win 5840 <mss 1460,sackOK,timestamp 1519088 0,nop,wscale 0> (DF)
22:53:56.466340 212.227.220.93.www > 213.6.220.71.61037: S 628941189:628941189(0) ack 643632370 win 32752 <mss 1460>
22:53:56.476834 213.6.220.71.61037 > 212.227.220.93.www: . ack 1 win 5840 (DF)
22:53:56.478153 213.6.220.71.61037 > 212.227.220.93.www: P 1:763(762) ack 1 win 5840 (DF)
22:53:56.736290 212.227.220.93.www > 213.6.220.71.61037: . ack 763 win 32752 (DF)
22:53:56.876276 212.227.220.93.www > 213.6.220.71.61037: P 1:206(205) ack 763 win 32752 (DF)
22:53:56.886986 213.6.220.71.61037 > 212.227.220.93.www: . ack 206 win 6432 (DF)
22:53:57.116275 212.227.220.93.www > 213.6.220.71.61037: . 206:1666(1460) ack 763 win 32752 (DF)
22:53:57.118256 213.6.220.71.61037 > 212.227.220.93.www: . ack 1666 win 8760 (DF)
22:53:57.296310 212.227.220.93.www > 213.6.220.71.61037: . 1666:3126(1460) ack 763 win 32752
22:53:57.298316 213.6.220.71.61037 > 212.227.220.93.www: . ack 3126 win 11680 (DF)
22:53:57.346314 212.227.220.93.www > 213.6.220.71.61037: P 3126:3558(432) ack 763 win 32752 (DF)
22:53:57.347377 213.6.220.71.61037 > 212.227.220.93.www: . ack 3558 win 14600 (DF)
22:53:57.356305 212.227.220.93.www > 213.6.220.71.61037: F 3558:3558(0) ack 763 win 32752
22:53:57.366990 213.6.220.71.61037 > 212.227.220.93.www: F 763:763(0) ack 3559 win 14600 (DF)
22:53:57.506349 212.227.220.93.www > 213.6.220.71.61037: . ack 764 win 32751 (DF)

[-- Attachment #3: server-out1 --]
[-- Type: application/octet-stream, Size: 714 bytes --]

22:54:16.311964 213.6.220.71.2013 > 212.227.220.93.www: S 567093009:567093009(0) win 32120 <mss 1460,sackOK,timestamp 1524338 0,nop,wscale 0> (DF)
22:54:16.466342 212.227.220.93.www > 213.6.220.71.2013: S 3414621432:3414621432(0) ack 567093010 win 32752 <mss 1460>
22:54:16.476925 213.6.220.71.2013 > 212.227.220.93.www: R 567093010:567093010(0) win 0 (DF)
22:54:19.306368 213.6.220.71.2013 > 212.227.220.93.www: S 567093009:567093009(0) win 32120 <mss 1460,sackOK,timestamp 1524638 0,nop,wscale 0> (DF)
22:54:19.506334 212.227.220.93.www > 213.6.220.71.2013: S 3417618392:3417618392(0) ack 567093010 win 32752 <mss 1460>
22:54:19.516813 213.6.220.71.2013 > 212.227.220.93.www: R 567093010:567093010(0) win 0 (DF)

[-- Attachment #4: server-out2 --]
[-- Type: application/octet-stream, Size: 1498 bytes --]

00:23:56.813058 213.6.115.242.2025 > 212.227.220.93.www: S 1946189867:1946189867(0) win 32120 <mss 1460,sackOK,timestamp 2062388 0,nop,wscale 0> (DF)
00:23:56.956273 212.227.220.93.www > 213.6.115.242.2025: S 416941753:416941753(0) ack 1946189868 win 32752 <mss 1460>
00:23:56.956486 213.6.115.242.2025 > 212.227.220.93.www: . ack 1 win 32120 (DF)
00:23:56.958195 213.6.115.242.2025 > 212.227.220.93.www: P 1:201(200) ack 1 win 32120 (DF)
00:23:57.176329 212.227.220.93.www > 213.6.115.242.2025: . ack 201 win 32752 (DF)
00:23:57.396334 212.227.220.93.www > 213.6.115.242.2025: P 1:206(205) ack 201 win 32752 (DF)
00:23:57.396618 213.6.115.242.2025 > 212.227.220.93.www: . ack 206 win 31915 (DF)
00:23:57.686328 212.227.220.93.www > 213.6.115.242.2025: . 206:1666(1460) ack 201 win 32752 (DF)
00:23:57.896312 212.227.220.93.www > 213.6.115.242.2025: . 1666:3126(1460) ack 201 win 32752
00:23:57.896606 213.6.115.242.2025 > 212.227.220.93.www: . ack 3126 win 30660 (DF)
00:23:57.956296 212.227.220.93.www > 213.6.115.242.2025: P 3126:3558(432) ack 201 win 32752 (DF)
00:23:57.976352 213.6.115.242.2025 > 212.227.220.93.www: . ack 3558 win 32120 (DF)
00:23:58.016350 212.227.220.93.www > 213.6.115.242.2025: F 3558:3558(0) ack 201 win 32752
00:23:58.016631 213.6.115.242.2025 > 212.227.220.93.www: . ack 3559 win 32119 (DF)
00:23:58.017914 213.6.115.242.2025 > 212.227.220.93.www: F 201:201(0) ack 3559 win 32120 (DF)
00:23:58.176296 212.227.220.93.www > 213.6.115.242.2025: . ack 202 win 32751 (DF)