Date: Tue, 19 Mar 2002 17:06:51 -0700 From: Colin Harford <colin.harford@mail.su.ualberta.ca> To: Doug White <dwhite@resnet.uoregon.edu>, <freebsd-stable@freebsd.org>, <abaugher@esc.pike.il.us> Subject: Re: Network stalls with 4.5 Message-ID: <B8BD20AB.8516%colin.harford@mail.su.ualberta.ca> In-Reply-To: <20020319154511.L80289-100000@resnet.uoregon.edu>
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On 19/3/02 4:48 PM, "Doug White" <dwhite@resnet.uoregon.edu> wrote: > On 19 Mar 2002, Aaron Baugher wrote: > >> To add to the previous info, here's a chunk of a tcpdump. I logged in >> through ssh, and ran 'top' to generate some traffic. My home machine >> (Mandrake Linux, connected with a modem) is 11.22.33.44, and the >> FreeBSD machine having the problem is 55.66.77.88. (I should stress >> that the problem occurs from several different client machines and >> OS's, so it's definitely caused at the server end.) > > This looks like simple packet loss on the network. Can you set up a > monitor port on the Cisco switch and confirm the packet that is retried is > actually making it onto the wire? Also set up other monitors downstream > and see if you can isolate where the packet disappears. > >> 09:41:22.371874 55.66.77.88.22 > 11.22.33.44.4257: P 33324:33472(148) ack 161 >> win 65535 [tos 0x10] >> 09:41:23.371716 55.66.77.88.22 > 11.22.33.44.4257: P 33324:33472(148) ack 161 >> win 65535 [tos 0x10] >> >> That's the same packet sent twice, right? >> >> 09:41:24.381831 55.66.77.88.22 > 11.22.33.44.4257: P 33472:33628(156) ack 161 >> win 65535 [tos 0x10] >> 09:41:24.629822 11.22.33.44.4257 > 55.66.77.88.22: . ack 33324 win 51360 (DF) >> [tos 0x10] >> 09:41:25.371763 55.66.77.88.22 > 11.22.33.44.4257: P 33324:33628(304) ack 161 >> win 65535 [tos 0x10] >> >> Now here's the same number (33324) as the doubled packet above, but >> with a different second number and size. > > The change in size is the system gluing the payloads of the two packets > together since the remote sent an ACK up to 33324. > >> 09:41:34.666565 11.22.33.44.4257 > 55.66.77.88.22: . ack 33324 win 51360 (DF) >> [tos 0x10] >> 09:41:34.666621 55.66.77.88.22 > 11.22.33.44.4257: P 33324:34336(1012) ack >> 161 win 65535 [tos 0x10] >> 09:41:35.147334 11.22.33.44.4257 > 55.66.77.88.22: . ack 34336 win 51360 (DF) >> [tos 0x10] > > Look like your network keeled over for 10 seconds. Bandwidth problems > downstream? > > Also make sure something downstream isn't, say, loosing the ARP entry for > it's default gateway. > > Doug White | FreeBSD: The Power to Serve > dwhite@resnet.uoregon.edu | www.FreeBSD.org > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-stable" in the body of the message I was having a similar situation as Aaron at home on both my FreeBSD machines € K6-3-450, 512 RAM, rl interface € K7-1.2Ghz, 1GB RAM, xl interface Both started happening in FreeBSD 4.5, both are connected to an internal 10/100 switch at 100T and are about 10 inches from each other... The k7 is a dual boot machine, and when I am in winblowdoze I do not have the same problem, so I have mostly ruled out hardware problems...(that and hardware has been tested in other situations without problems) I updated both machines this past weekened, to RELENG_4_5 and no longer do I have this problem. HTH Colin Harford Systems and Network Administrator Apple Product Professional ================================= Computer and Network Support University of Alberta Students' Union Phone: (780) 492-4241 Fax: (780) 492-4643 http://www.su.ualberta.ca "I sense much NT in you, NT leads to Blue Screen. Blue Screen leads to downtime, downtime leads to suffering. NT is the path to the darkside." - Unknown Unix Jedi To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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