From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Dan A. Dickey" Subject: TCP Hang (or close to it): Windows XP -> Linux (w/tcp_bic) Date: Fri, 29 Oct 2004 09:25:48 -0500 Sender: netdev-bounce@oss.sgi.com Message-ID: <200410290925.48955.dan.dickey@savvis.net> Reply-To: dan.dickey@savvis.net Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: To: netdev@oss.sgi.com Content-Disposition: inline Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org All, We are able to reproduce what appears to be a tcp hang with Windows XP sending to a Linux box (2.6.7 kernel) that has tcp_bic turned on. At the moment, I'm unsure that tcp_bic has anything to do with it - I'll be testing with tcp_bic turned off today to see if I can reproduce this problem or not. I'm looking for someone to help me determine what the cause of this hang is - I have a 3MB ethereal capture file that I can send if you think you can help out. Let me know, and I'll send you the file and some more information about the application and what we are doing. Just in case this might help you to figure it out, here is a small portion of the display from ethereal at the point of failure. 192.168.168.126 is the Windows XP machine, and 192.168.168.25 is the Linux box. 14:25:58.260109 IP 192.168.168.25.15100 > 192.168.168.126.2519: . ack 1101042 win 39272 14:25:58.260116 IP 192.168.168.25.15100 > 192.168.168.126.2519: . ack 1102502 win 42192 14:25:58.260133 IP 192.168.168.126.2519 > 192.168.168.25.15100: . 1102502:1103962(1460) ack 1 win 65535 14:25:58.260143 IP 192.168.168.25.15100 > 192.168.168.126.2519: . ack 1103962 win 45112 14:25:58.260147 IP 192.168.168.126.2519 > 192.168.168.25.15100: . 1103962:1105422(1460) ack 1 win 65535 14:25:58.260155 IP 192.168.168.25.15100 > 192.168.168.126.2519: . ack 1105422 win 48032 14:25:58.260184 IP 192.168.168.126.2519 > 192.168.168.25.15100: . 1105422:1106882(1460) ack 1 win 65535 14:25:58.260191 IP 192.168.168.126.2519 > 192.168.168.25.15100: . 1106882:1108342(1460) ack 1 win 65535 14:25:58.260206 IP 192.168.168.126.2519 > 192.168.168.25.15100: . 1108342:1109802(1460) ack 1 win 65535 14:25:58.260228 IP 192.168.168.25.15100 > 192.168.168.126.2519: . ack 1106882 win 50952 14:25:58.260252 IP 192.168.168.25.15100 > 192.168.168.126.2519: . ack 1108342 win 53872 14:25:58.260273 IP 192.168.168.25.15100 > 192.168.168.126.2519: . ack 1109802 win 56792 14:25:58.260279 IP 192.168.168.25.15100 > 192.168.168.126.2519: . ack 1111262 win 59712 14:25:58.260286 IP 192.168.168.25.15100 > 192.168.168.126.2519: . ack 1112722 win 62632 14:25:58.260293 IP 192.168.168.25.15100 > 192.168.168.126.2519: . ack 1114182 win 16 14:25:58.260348 IP 192.168.168.25.15100 > 192.168.168.126.2519: . ack 1114506 win 16 14:25:58.534331 IP 192.168.168.126.2451 > 192.168.168.25.15100: . 160:176(16) ack 1 win 65535 14:25:58.534493 IP 192.168.168.25.15100 > 192.168.168.126.2451: . ack 176 win 16 14:26:03.237624 IP 192.168.168.126.2519 > 192.168.168.25.15100: . 1114506:1114522(16) ack 1 win 65535 14:26:03.237803 IP 192.168.168.25.15100 > 192.168.168.126.2519: . ack 1114522 win 16 14:26:03.565752 IP 192.168.168.126.2451 > 192.168.168.25.15100: . 176:192(16) ack 1 win 65535 14:26:03.565914 IP 192.168.168.25.15100 > 192.168.168.126.2451: . ack 192 win 16 14:26:08.269049 IP 192.168.168.126.2519 > 192.168.168.25.15100: . 1114522:1114538(16) ack 1 win 65535 14:26:08.269217 IP 192.168.168.25.15100 > 192.168.168.126.2519: . ack 1114538 win 16 14:26:08.597185 IP 192.168.168.126.2451 > 192.168.168.25.15100: . 192:208(16) ack 1 win 65535 14:26:08.597347 IP 192.168.168.25.15100 > 192.168.168.126.2451: . ack 208 win 16 14:26:13.300469 IP 192.168.168.126.2519 > 192.168.168.25.15100: . 1114538:1114554(16) ack 1 win 65535 14:26:13.300640 IP 192.168.168.25.15100 > 192.168.168.126.2519: . ack 1114554 win 16 14:26:13.628603 IP 192.168.168.126.2451 > 192.168.168.25.15100: . 208:224(16) ack 1 win 65535 14:26:13.628774 IP 192.168.168.25.15100 > 192.168.168.126.2451: . ack 224 win 16 14:26:18.331909 IP 192.168.168.126.2519 > 192.168.168.25.15100: . 1114554:1114570(16) ack 1 win 65535 14:26:18.332075 IP 192.168.168.25.15100 > 192.168.168.126.2519: . ack 1114570 win 16 14:26:18.660013 IP 192.168.168.126.2451 > 192.168.168.25.15100: . 224:240(16) ack 1 win 65535 14:26:18.660174 IP 192.168.168.25.15100 > 192.168.168.126.2451: . ack 240 win 16 I'm not sure how well this is going to come across, but as I said - I can send the capture file. Please help! Thanks in advance. (My concern is the window on the Linux side dropping from 62632 to 16 at the 14:25:58.260293 point - this just doesn't seem right). -Dan -- Dan A. Dickey dan.dickey@savvis.net SAVVIS Transforming Information Technology