Weird link down problem

giggi

New Member
Joined
Jan 4, 2022
Messages
4
Reaction score
0
Credits
43
Hello, under Debian 10 I have a very strange problem: eth0 goes down intermittently, without any errors and randomly; it just
goes down, ip link reports "no carrier", ethtool shows "Link detected: no" and tcpdump shows no packets at all
If I do a "ethtool -r eth0" link comes up again; the same happens when I do a NIC test with ethtool; from this moment
until the next random stop eth0 works perfectly, at 1Gbps speed
Some logs:
[mar gen 4 23:07:20 2022] igb 0000:06:00.0 eth0: igb: eth0 NIC Link is Down
[mar gen 4 23:22:53 2022] igb 0000:06:00.0: offline testing starting <---- I started a test using ethtool -t eth0
[mar gen 4 23:22:57 2022] igb 0000:06:00.0 eth0: igb: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
[mar gen 4 23:22:58 2022] igb 0000:06:00.0: testing shared interrupt
[mar gen 4 23:23:08 2022] igb 0000:06:00.0 eth0: igb: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX
[mar gen 4 23:23:59 2022] igb 0000:06:00.0: online testing starting

I'm pretty sure that this NIC works without any problem with a cheap switch; but now it's connected on an ethernet port of
a modem and it also had the problems when it was connected to a linksys LRT214 (little firewall/vpn appliance)
I tried to set autoneg off using ethtool (ethtool -s eth0 autoneg off) but ethtool continue to show " Auto-negotiation: on"
I've changed the cable three times; I suspect the NIC is broken, but there are no errors in any log, and ethtool -t eth0
shows "The test result is PASS"
Any ideas / suggestion / direction ?
Thank you
 


I forgot to write: nic is (from lspci)
"Ethernet controller: Intel Corporation I350 Gigabit Network Connection"
It's an onboard NIC of a (very) old PowerEdge T620
 
I forgot to write: nic is (from lspci)
"Ethernet controller: Intel Corporation I350 Gigabit Network Connection"
It's an onboard NIC of a (very) old PowerEdge T620
Maybe dmesg the driver and see if that provides any clues.

If the nic is that old it may be on it's way out.
Maybe try a usb wireless dongle.

The Power Edge machines that Dell made date back to 2007. So yeah, that's pretty old.


Is there a slot on the mobo for you to install another nic card?
 
Hi, I have slots to install another nic, but I'd like to be sure that the nic is broken; in dmesg I cannot find anything useful
The workaround is an ethtool -r eth0 on crontab, just for a few hours :)
The usb dongle could be an idea, but I have usb2 ports only
Thank you
 
Most usb wifi's are still usb 2 compatible. But if it were me I'd go for the new Ethernet card in the slot available. Since this obviously is not a wireless need. This will give you some idea of the costs.
 
Last edited:
Hi, I'm sorry, while writing I was thinking of a USB ethernet, not wifi: I need 1Gbps and that's why I can't use a USB2 port.
I'll probably buy another card; it's just the first time I see this behaviour from a NIC and the OS, NIC not working and no errors
anywhere, but there's a first time for everything
Thank you
 
Hi, I have slots to install another nic, but I'd like to be sure that the nic is broken; in dmesg I cannot find anything useful
The workaround is an ethtool -r eth0 on crontab, just for a few hours :)
The usb dongle could be an idea, but I have usb2 ports only
Thank you
You're welcome-
 

Members online


Top