The interface is a Comtrol Hostess SV11, and it's connected via a 128Kb/s
Kilostream line to a Cisco 7513. The problem shows up on both the original
486DX/66 machine and the P-II 350 which it was swapped for, to see if it would
help.
Here's a sample trace of a connection to an external web site, taken from
both their end and ours. This is repeatable, as shown by the second almost
identical pair of traces.
This also shows up on connections directly from our router box to
a web server belonging to our ISP, so isn't an external problem. However, it
does seem to happen more often when our box is routing, which makes me think
it might be related to the load on our router.
I've tried swapping the 486 for a P-II, I've shifted the Hostess to use an IRQ
on the primary PIC and used irqtune to give it priority. I've tried swapping
the Ethernet NIC from a DEC 21140 (SMC Etherpower) to a 21142 (Kingston
KNE100TX) and even an Intel EtherExpress 16 (it was lying around). The latter
made it worse, so it's back on the 21140 now. I've used all three dma
possibilities - none, tx only, both. I've also killed klogd, and commented out
the 'spurious tx done' printk, which was happening after every outgoing packet.
I've set the IDE disks to unmaskirq.
Trace taken at Robinson College:
13:45:42.035885 194.205.184.34.3393 > 131.111.217.1.80: S 3608638051:3608638051(0) win 32120 <mss 1460,sackOK,timestamp 10627710[|tcp]> (DF)
13:45:42.045885 131.111.217.1.80 > 194.205.184.34.3393: S 129232784:129232784(0) ack 3608638052 win 32768 <mss 1460> (DF)
; No response to this, so we resend it.
13:45:43.565885 131.111.217.1.80 > 194.205.184.34.3393: S 129232784:129232784(0) ack 3608638052 win 32768 <mss 1460> (DF)
13:45:43.625885 194.205.184.34.3393 > 131.111.217.1.80: . ack 1 win 32120 (DF)
13:45:45.165885 194.205.184.34.3393 > 131.111.217.1.80: P 1:712(711) ack 1 win 32120 (DF)
13:45:45.165885 131.111.217.1.80 > 194.205.184.34.3393: . 1:1461(1460) ack 712 win 32057 (DF)
13:45:45.165885 131.111.217.1.80 > 194.205.184.34.3393: FP 1461:2597(1136) ack 712 win 32057 (DF)
13:45:45.285885 194.205.184.34.3393 > 131.111.217.1.80: . ack 1461 win 30660 (DF)
13:45:45.365885 194.205.184.34.3393 > 131.111.217.1.80: . ack 2598 win 30660 (DF)
; Waiting for response, which has to be resent before we get it.
13:45:51.355885 194.205.184.34.3393 > 131.111.217.1.80: F 712:712(0) ack 2598 win 32120 (DF)
13:45:51.355885 131.111.217.1.80 > 194.205.184.34.3393: . ack 713 win 32056 (DF)
Trace taken at Axiom:
12:47:22.081731 194.205.184.34.3393 > 131.111.217.1.80: S 3608638051:3608638051(0) win 32120 <mss 1460,sackOK,timestamp 10627710[|tcp]> (DF)
12:47:22.111731 131.111.217.1.80 > 194.205.184.34.3393: S 129232784:129232784(0) ack 3608638052 win 32768 <mss 1460> (DF)
12:47:22.111731 194.205.184.34.3393 > 131.111.217.1.80: . ack 1 win 32120 (DF)
12:47:22.111731 194.205.184.34.3393 > 131.111.217.1.80: P 1:712(711) ack 1 win 32120 (DF)
; The above two packets evidently didn't get through, so www.robinson resends the SYN
12:47:23.671731 131.111.217.1.80 > 194.205.184.34.3393: S 129232784:129232784(0) ack 3608638052 win 32768 <mss 1460> (DF)
12:47:23.671731 194.205.184.34.3393 > 131.111.217.1.80: . ack 1 win 32120 (DF)
12:47:25.111731 194.205.184.34.3393 > 131.111.217.1.80: P 1:712(711) ack 1 win 32120 (DF)
12:47:25.331731 131.111.217.1.80 > 194.205.184.34.3393: . 1:1461(1460) ack 712 win 32057 (DF)
12:47:25.331731 194.205.184.34.3393 > 131.111.217.1.80: . ack 1461 win 30660 (DF)
12:47:25.401731 131.111.217.1.80 > 194.205.184.34.3393: FP 1461:2597(1136) ack 712 win 32057 (DF)
12:47:25.401731 194.205.184.34.3393 > 131.111.217.1.80: . ack 2598 win 30660 (DF)
12:47:25.411731 194.205.184.34.3393 > 131.111.217.1.80: F 712:712(0) ack 2598 win 32120 (DF)
; No ack for the above, so we resend it.
12:47:31.401731 194.205.184.34.3393 > 131.111.217.1.80: F 712:712(0) ack 2598 win 32120 (DF)
12:47:31.431731 131.111.217.1.80 > 194.205.184.34.3393: . ack 713 win 32056 (DF)
Second attempt...
Robinson
13:46:23.765885 194.205.184.34.3396 > 131.111.217.1.80: S 3655406386:3655406386(0) win 32120 <mss 1460,sackOK,timestamp 10631884[|tcp]> (DF)
13:46:23.765885 131.111.217.1.80 > 194.205.184.34.3396: S 129244928:129244928(0) ack 3655406387 win 32768 <mss 1460> (DF)
13:46:25.095885 131.111.217.1.80 > 194.205.184.34.3396: S 129244928:129244928(0) ack 3655406387 win 32768 <mss 1460> (DF)
13:46:25.115885 194.205.184.34.3396 > 131.111.217.1.80: . ack 1 win 32120 (DF)
13:46:26.895885 194.205.184.34.3396 > 131.111.217.1.80: P 1:712(711) ack 1 win 32120 (DF)
13:46:26.895885 131.111.217.1.80 > 194.205.184.34.3396: . 1:1461(1460) ack 712 win 32057 (DF)
13:46:26.895885 131.111.217.1.80 > 194.205.184.34.3396: FP 1461:2597(1136) ack 712 win 32057 (DF)
13:46:27.025885 194.205.184.34.3396 > 131.111.217.1.80: . ack 1461 win 30660 (DF)
13:46:27.105885 194.205.184.34.3396 > 131.111.217.1.80: . ack 2598 win 30660 (DF)
13:46:33.095885 194.205.184.34.3396 > 131.111.217.1.80: F 712:712(0) ack 2598 win 32120 (DF)
13:46:33.095885 131.111.217.1.80 > 194.205.184.34.3396: . ack 713 win 32056 (DF)
Axiom
12:48:03.821731 194.205.184.34.3396 > 131.111.217.1.80: S 3655406386:3655406386(0) win 32120 <mss 1460,sackOK,timestamp 10631884[|tcp]> (DF)
12:48:03.861731 131.111.217.1.80 > 194.205.184.34.3396: S 129244928:129244928(0) ack 3655406387 win 32768 <mss 1460> (DF)
12:48:03.861731 194.205.184.34.3396 > 131.111.217.1.80: . ack 1 win 32120 (DF)
12:48:03.861731 194.205.184.34.3396 > 131.111.217.1.80: P 1:712(711) ack 1 win 32120 (DF)
12:48:05.171731 131.111.217.1.80 > 194.205.184.34.3396: S 129244928:129244928(0) ack 3655406387 win 32768 <mss 1460> (DF)
12:48:05.171731 194.205.184.34.3396 > 131.111.217.1.80: . ack 1 win 32120 (DF)
12:48:06.861731 194.205.184.34.3396 > 131.111.217.1.80: P 1:712(711) ack 1 win 32120 (DF)
12:48:07.081731 131.111.217.1.80 > 194.205.184.34.3396: . 1:1461(1460) ack 712 win 32057 (DF)
12:48:07.081731 194.205.184.34.3396 > 131.111.217.1.80: . ack 1461 win 30660 (DF)
12:48:07.151731 131.111.217.1.80 > 194.205.184.34.3396: FP 1461:2597(1136) ack 712 win 32057 (DF)
12:48:07.161731 194.205.184.34.3396 > 131.111.217.1.80: . ack 2598 win 30660 (DF)
12:48:07.161731 194.205.184.34.3396 > 131.111.217.1.80: F 712:712(0) ack 2598 win 32120 (DF)
12:48:13.151731 194.205.184.34.3396 > 131.111.217.1.80: F 712:712(0) ack 2598 win 32120 (DF)
12:48:13.191731 131.111.217.1.80 > 194.205.184.34.3396: . ack 713 win 32056 (DF)
---- ---- ----
David Woodhouse David.Woodhouse@mvhi.com Office: (+44) 1223 810302
Project Leader, Process Information Systems Mobile: (+44) 976 658355
Axiom (Cambridge) Ltd., Swaffham Bulbeck, Cambridge, CB5 0NA, UK.
finger dwmw2@ferret.lmh.ox.ac.uk for PGP key.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/