Very strange network issue
Hi,
I have a debian/woody + some sid packages which includes a very strange issue.
Whenever I connect to certain site with opera, netscape, konqueror, lynx or
links, I never get an ackgowledge packet. Therefore, the http connection
always fail with a "no answer" kind of message. The sites which show this
behaviour are
www.sun.com
www.zdnet.com
www.voyages-sncf.com
www.canon.co.jp
In order to try to understand, I set up a tcpdump on my NAT firewall :
Here is what happens when I use a debian system (192.168.0.100)
20:41:43.019608 192.168.0.100.4271 > www.sun.com.www: SWE
1044463694:1044463694(0) win 5840 <mss 1460,sackOK,timestamp 8529418
0,nop,wscale 0> (DF)
0x0000 4500 003c 5d9b 4000 4006 fa10 c0a8 0064 E..<].@.@......d
0x0010 c012 61f1 10af 0050 3e41 404e 0000 0000 ..a....P>A@N....
0x0020 a0c2 16d0 974c 0000 0204 05b4 0402 080a .....L..........
0x0030 0082 260a 0000 0000 0103 0300 ..&.........
Here is what happens with a Windows machine connected to the same NAT
firewall :
20:42:02.203155 192.168.0.101.1782 > www.sun.com.www: S 39886669:39886669(0)
win 8192 <mss 1460,nop,nop,sackOK> (DF)
0x0000 4500 0030 4144 4000 8006 d672 c0a8 0065 E..0AD@....r...e
0x0010 c012 61f1 06f6 0050 0260 9f4d 0000 0000 ..a....P.`.M....
0x0020 7002 2000 d71a 0000 0204 05b4 0101 0402 p...............
20:42:02.396883 www.sun.com.www > 192.168.0.101.1782: S
109390000:109390000(0) ack 39886670 win 64240 <mss 1460>
0x0000 4500 002c c755 0000 eb06 2565 c012 61f1 E..,.U....%e..a.
0x0010 c0a8 0065 0050 06f6 0685 28b0 0260 9f4e ...e.P....(..`.N
0x0020 6012 faf0 e1ea 0000 0204 05b4
Here is what happens with the same debian system connecting to www.apple.com
22:06:09.023187 192.168.0.100.4370 > www.apple.com.www: SWE
2111225404:2111225404(0) win 5840 <mss 1460,sackOK,timestamp 9035972
0,nop,wscale 0> (DF) [tos 0x10]
0x0000 4510 003c 5ef8 4000 4006 084f c0a8 0064 E..<^.@.@..O...d
0x0010 11fe 005b 1112 0050 7dd6 be3c 0000 0000 ...[...P}..<....
0x0020 a0c2 16d0 2e4f 0000 0204 05b4 0402 080a .....O..........
0x0030 0089 e0c4 0000 0000 0103 0300 ............
22:06:09.249325 www.apple.com.www > 192.168.0.100.4370: S
1063183829:1063183829(0) ack 2111225405 win 32768 <mss 512,nop,wscale
0,nop,nop,timestamp 6565777 9035972>
0x0000 4500 003c 029b 0000 2e06 b6bc 11fe 005b E..<...........[
0x0010 c0a8 0064 0050 1112 3f5e e5d5 7dd6 be3d ...d.P..?^..}..=
0x0020 a012 8000 7759 0000 0204 0200 0103 0300 ....wY..........
0x0030 0101 080a 0064 2f91 0089 e0c4 .....d/.....
Obviously, only when connecting to www.sun.com from the debian system, I get
no reply. I tried on all my debian machines : same problem. Some sites such
as sun, zdnet or voyages-sncf.com do not seem reply. Most other sites work
perfectly.
I tried also on a friend's debian system (woody/sid). Everything got fine for
him including sun and zdnet.
Does anyone have an idea ? How should I proceed to understand what is
happening ?
Regards,
JPS.
--
Jean-Paul Smets-Solanes <jp@smets.com>
GPG Fingerprint: 40FF FA78 75AA 680D 8BB4 EEF9 539A 79CC CB8E 5F01
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