2009/4/21 Mangesh S. Umbarje <mangesh at gmrt.ncra.tifr.res.in> > > I have checked the physical connectivity which is perfectly fine. > This machine is very critical which we need to keep running as much as > possible. So I had gone to older kernel 2.6.18-92.1.17.el5. But along with > this kernel, I had added one more Dlink ethernet card which shows to be > > 05:09.0 Ethernet controller: D-Link System Inc DGE-530T Gigabit Ethernet > Adapter (rev 11) (rev 11) > > and it uses the skge driver. > > So I could test the machine with this new card and > kernel-2.6.18-92.1.17.el5 togather. Still I do get the network breaks but > the frequency reduced to factor of Ten. The corresponding messages seen in > the /var/log/messages are as follow. > > Apr 21 10:18:32 kernel: skge eth1: Link is down. > Apr 21 10:18:36 kernel: skge eth1: Link is up at 1000 Mbps, full duplex, > flow control none > Apr 21 10:18:55 kernel: skge eth1: Link is down. > Apr 21 10:18:57 kernel: skge eth1: Link is up at 1000 Mbps, full duplex, > flow control none > Apr 21 10:18:58 kernel: skge eth1: Link is down. > Apr 21 10:19:01 kernel: skge eth1: Link is up at 1000 Mbps, full duplex, > flow control none > So, with a preupdate kernel and a different NIC, which uses different drivers, you're still getting the problems... I'm more convinced of a physical problem... Have you tried a different switch port? Does the cabling run past a laser printer? Does the cabling run parallel to some electrical cabling with intermittent high load, such as to cooling or heating systems? If you run the port at 100Mbps do you still get the same problem? How did you confirm the physical connectivity was fine? d -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.centos.org/pipermail/centos/attachments/20090421/3248dc7b/attachment-0005.html>