# What does "e1000_watchdog: NIC Link is Down" imply? [Solved]

## Akkara

Recently I saw this in my logs.  Any idea what it might mean?  Hardware problems? The machine's otherwise been running fine over a year; I've never seen this message before.

```
Jul  3 19:36:55 host e1000: eth0: e1000_watchdog: NIC Link is Down

Jul  3 19:37:07 host e1000: eth0: e1000_watchdog: NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX

Jul  3 19:37:13 host e1000: eth0: e1000_watchdog: NIC Link is Down

Jul  3 19:37:15 host e1000: eth0: e1000_watchdog: NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX/TX
```

There was no other network-related messages in the logs before or afterwards.

Could it be some sort of network reset from intrustion?  There's nothing else interesting in the logs and I keep a tail -f running so even if someone edited the file afterwards I would have seen something.

I had tried searching google for the term but mostly is mentions issues in regard to a virtual machine.  I'm not using VM here.

There's not much interesting network-wise on this box: ntpd, occasionally sshd if I'll be needing to get in (sshd wasn't running at that time; besides it is configured to accept key + passphrase only), and the usual web-browsing and stuff.

It is also kept updated, usually weekly.

 *uname -r wrote:*   

> 2.6.24-gentoo-r8

 

Edit/addendum:

Mobo is Asus-P5KC with E6850 dual-core.  Using a old Intel 82541PI controller for net because, back when I set the machine up, using the net at the same time as a lot of disc activity cause it to lock up.  The card worked fine so stuck with that.  (Someday I should try it again to see if it was some kernel/driver issue that's since been fixed, or if the mobo's ethernet is broken.)Last edited by Akkara on Sat Jul 05, 2008 8:57 am; edited 1 time in total

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## mjf55

A google search on e1000_watchdog shows that you are not alone.  A sampling of hits, show possible cable or router/switch or NIC issue but nothing definitive.  This has need been on different linux distros, in VMware, many places.  You could try some cable swapping, router substitution (if possible), but it appears to be a generic issue that is not solved yet.

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## Hu

I have observed this message for the interface associated with my cable modem.  In every case where I was present to observe it, the kernel messages were exactly correlated with the cable modem losing sync with the ISP.  When the cable modem failed and ceased passing traffic to the Internet, I got a "NIC link is down" message.  When the modem resynchronized with the ISP, I got a "NIC link is up" message.  I have never observed connectivity problems outside of the times when the modem was flashing its lights in a pattern that the manual indicates means failure.  That is, I have no known hardware problems with the NIC or the modem.  Assuming your messages appeared for the same reason mine do, you had a transient connectivity failure with your ISP and there is nothing to fix.

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## Akkara

Thanks for the answers!

It happened again and this time I got to see it as it was happening.  Indeed the network switch and modem went down -- because the UPS they on failed and it has been momentarily glitching off and on every few hours.

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