2009/4/21 Mangesh S. Umbarje
<mangesh@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?