[feisty] can not surf to some sites

[Jos Dehaes]

Binary package hint: linux-image-generic

I frequently use the belgian site www.verkeerscentrum.be. I can no longer access it from within feisty. I have tried firefox, epiphany, wget, all without success. With another machine that is still running edgy has no problems connecting. This appears to be a TCP/IP problem (kernel?).

A sniff with tcpdump reveals the following (tried to get the index page of said site with wget):
Feisty:
jos@duet-feisty ~ $ sudo tcpdump -i eth1 port 80
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth1, link-type EN10MB (Ethernet), capture size 96 bytes
21:48:48.218219 IP duet.sourcery.be.43786 > www.verkeerscentrum.be.www: S 3485545750:3485545750(0) win 5840 <mss 1460,sackOK,timestamp 29689296 0,nop,wscale 5>
21:48:48.244487 IP www.verkeerscentrum.be.www > duet.sourcery.be.43786: S 1471224515:1471224515(0) ack 3485545751 win 5840 <mss 1460,nop,nop,sackOK,nop,wscale 0>
21:48:48.244553 IP duet.sourcery.be.43786 > www.verkeerscentrum.be.www: . ack 1 win 183
21:48:48.244828 IP duet.sourcery.be.43786 > www.verkeerscentrum.be.www: P 1:111(110) ack 1 win 183
21:48:48.272990 IP www.verkeerscentrum.be.www > duet.sourcery.be.43786: . ack 111 win 5840
21:49:31.852600 IP duet.sourcery.be.43786 > www.verkeerscentrum.be.www: F 111:111(0) ack 1 win 183
21:49:32.077865 IP duet.sourcery.be.43786 > www.verkeerscentrum.be.www: F 111:111(0) ack 1 win 183
21:49:32.533896 IP duet.sourcery.be.43786 > www.verkeerscentrum.be.www: F 111:111(0) ack 1 win 183
21:49:33.446141 IP duet.sourcery.be.43786 > www.verkeerscentrum.be.www: F 111:111(0) ack 1 win 183
21:49:35.270051 IP duet.sourcery.be.43786 > www.verkeerscentrum.be.www: F 111:111(0) ack 1 win 183

10 packets captured
11 packets received by filter
0 packets dropped by kernel

With edgy immideately after this:
jos@quattro:~$ tcpdump port 80
tcpdump: no suitable device found
jos@quattro:~$ sudo tcpdump -i eth0 port 80
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
21:50:13.861782 IP quattro.sourcery.be.39435 > www.verkeerscentrum.be.www: S 1247540388:1247540388(0) win 5840 <mss 1460,sackOK,timestamp 475837292 0,nop,wscale 2>
21:50:13.902859 IP www.verkeerscentrum.be.www > quattro.sourcery.be.39435: S 2302521251:2302521251(0) ack 1247540389 win 5840 <mss 1460,nop,nop,sackOK,nop,wscale 0>
21:50:13.902884 IP quattro.sourcery.be.39435 > www.verkeerscentrum.be.www: . ack 1 win 1460
21:50:13.903005 IP quattro.sourcery.be.39435 > www.verkeerscentrum.be.www: P 1:111(110) ack 1 win 1460
21:50:13.930066 IP www.verkeerscentrum.be.www > quattro.sourcery.be.39435: . ack 111 win 5840
21:50:13.936643 IP www.verkeerscentrum.be.www > quattro.sourcery.be.39435: P 1:582(581) ack 111 win 5840
21:50:13.936676 IP quattro.sourcery.be.39435 > www.verkeerscentrum.be.www: . ack 582 win 1751
21:50:13.946610 IP quattro.sourcery.be.39435 > www.verkeerscentrum.be.www: P 111:245(134) ack 582 win 1751
21:50:14.005304 IP www.verkeerscentrum.be.www > quattro.sourcery.be.39435: . ack 245 win 5840
21:50:14.033681 IP www.verkeerscentrum.be.www > quattro.sourcery.be.39435: . 582:2042(1460) ack 245 win 5840
21:50:14.074401 IP quattro.sourcery.be.39435 > www.verkeerscentrum.be.www: . ack 2042 win 2481
21:50:14.327453 IP www.verkeerscentrum.be.www > quattro.sourcery.be.39435: P 2042:3502(1460) ack 245 win 5840
21:50:14.327483 IP quattro.sourcery.be.39435 > www.verkeerscentrum.be.www: . ack 3502 win 3211
21:50:14.356874 IP www.verkeerscentrum.be.www > quattro.sourcery.be.39435: . 3502:4962(1460) ack 245 win 5840
21:50:14.356901 IP quattro.sourcery.be.39435 > www.verkeerscentrum.be.www: . ack 4962 win 3941
21:50:14.357582 IP www.verkeerscentrum.be.www > quattro.sourcery.be.39435: P 4962:6422(1460) ack 245 win 5840
21:50:14.357593 IP quattro.sourcery.be.39435 > www.verkeerscentrum.be.www: . ack 6422 win 4671
21:50:14.380247 IP www.verkeerscentrum.be.www > quattro.sourcery.be.39435: . 6422:7882(1460) ack 245 win 5840
21:50:14.380275 IP quattro.sourcery.be.39435 > www.verkeerscentrum.be.www: . ack 7882 win 5401
21:50:14.637695 IP www.verkeerscentrum.be.www > quattro.sourcery.be.39435: P 7882:9342(1460) ack 245 win 5840
21:50:14.637722 IP quattro.sourcery.be.39435 > www.verkeerscentrum.be.www: . ack 9342 win 6131
21:50:14.638362 IP www.verkeerscentrum.be.www > quattro.sourcery.be.39435: P 9342:10802(1460) ack 245 win 5840
21:50:14.638369 IP quattro.sourcery.be.39435 > www.verkeerscentrum.be.www: . ack 10802 win 6861
21:50:14.641127 IP www.verkeerscentrum.be.www > quattro.sourcery.be.39435: . 10802:12262(1460) ack 245 win 5840
21:50:14.641140 IP quattro.sourcery.be.39435 > www.verkeerscentrum.be.www: . ack 12262 win 7591
21:50:14.669202 IP www.verkeerscentrum.be.www > quattro.sourcery.be.39435: P 9342:10802(1460) ack 245 win 5840
21:50:14.669233 IP quattro.sourcery.be.39435 > www.verkeerscentrum.be.www: . ack 12262 win 7591 <nop,nop,sack 1 {9342:10802}>
21:50:14.669862 IP www.verkeerscentrum.be.www > quattro.sourcery.be.39435: . 10802:12262(1460) ack 245 win 5840
21:50:14.669874 IP quattro.sourcery.be.39435 > www.verkeerscentrum.be.www: . ack 12262 win 7591 <nop,nop,sack 1 {10802:12262}>
21:50:14.676198 IP www.verkeerscentrum.be.www > quattro.sourcery.be.39435: P 12262:12807(545) ack 245 win 5840
21:50:14.676226 IP quattro.sourcery.be.39435 > www.verkeerscentrum.be.www: . ack 12807 win 8321
21:50:14.676570 IP quattro.sourcery.be.39435 > www.verkeerscentrum.be.www: F 245:245(0) ack 12807 win 8321
21:50:14.707009 IP www.verkeerscentrum.be.www > quattro.sourcery.be.39435: F 12807:12807(0) ack 246 win 5840
21:50:14.707044 IP quattro.sourcery.be.39435 > www.verkeerscentrum.be.www: . ack 12808 win 8321

34 packets captured
68 packets received by filter
0 packets dropped by kernel
jos@quattro:~$

[Jos Dehaes (jos-dehaes)]

Rebooting the machine in edgy (which is still installed on another partition) shows that it is not a hardware or network problem. I can perfectly connect in edgy. In feisty I can not.

[Bret Towe (magnade)]

Jos:
I think you will find that doing the below command as root
(or via sudo) will allow the url to load in feisty

echo "0" > /proc/sys/net/ipv4/tcp_window_scaling

[Jos Dehaes (jos-dehaes)]

Indeed, this works. Why is this not the default then?

[Jos Dehaes (jos-dehaes)]

Some googling turned up the following link:

http://inodes.org/blog/2006/09/06/tcp-window-scaling-and-kernel-2617/

Ubuntu should set the old buffer sizes by default!

[Ron (rongeens8)]

Confirm this bug, I also bumped into it. No idea where the scaling gets borked though.

[Launchpad Janitor (janitor)]

Beginning with the Hardy Heron 8.04 development cycle, all open Ubuntu kernel bugs need to be reported against the "linux" kernel package. We are automatically migrating this bug to the new "linux" package. However, development has already began for the upcoming Intrepid Ibex 8.10 release. It would be helpful if you could test the upcoming release and verify if this is still an issue - http://www.ubuntu.com/testing . If the issue still exists, please update this report by changing the Status of the "linux" task from "Incomplete" to "New". We appreciate your patience and understanding as we make this transition. Thanks!