on 9-5-2008 4:51 PM Gordon Messmer spake the following: > Stephen Harris wrote: >> >> Sounds like the remote server may actually be busy and the number of >> outstanding connections is reaching the listen() backlog queue, so the >> remote server isn't doing an accept() and so the three way handshake >> isn't completing. > > That thought crossed my mind, too. However, it doesn't explain why the > problem only affects new connections from Linux hosts. Also, I believe > that the listen queue is per-port, and this problem affects all ports > equally, including oddball ports used by the web server. I'm the only > one connecting to those ports. > > There are certainly differences between the SYN packets from Linux hosts > and those from Windows. On Linux, I see a window size of 5840, and tcp > options: MSS=1460, SACK permitted, timestamps, and window scale: 7. > > On Windows, the window size is 65535, MSS=1460, and SACK permitted. > > However, I have no idea why any of those differences would cause a > problem intermittently. Unless there is a router in between somewhere that is broken on its dealing with window scaling. I have had that problem in the past. -- MailScanner is like deodorant... You hope everybody uses it, and you notice quickly if they don't!!!! -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 250 bytes Desc: OpenPGP digital signature URL: <http://lists.centos.org/pipermail/centos/attachments/20080908/53a13bdf/attachment-0005.sig>