Posted on July 15, 2020 4:09 pm
 |  Asked by Brian Knoll
 |  69 views
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We had a port go error-disabled:

%ETH-4-ERRDISABLE: link-interrupt-storm error detected on Ethernet30

I’m trying to get to the root cause of this. What is a ‘link-interrupt-storm’? What things might trigger that?

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Posted by Shreyas Ruwala
Answered on July 15, 2020 4:23 pm

Hi Brian,

 

There are indication on Ethernet x, there is an excessive error rate on the link causing rapid state changes.
The contribution can be due to bad cable, transceiver, dirty fiber, patch panel issues.
To begin with can you please share the following:
1. The connection details Switch A [etx] ------patch panel if any-------[ety] SwitchB
2.Check any L1 error at interface

#show int etx
3.Mac and phy detail [2 iterations from both end]

#show int etx mac de
#show int ety phy detail

Br,
Shreyas Ruwala

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Posted by prajwala an
Answered on July 15, 2020 5:06 pm

Hi Brian,

Usually link-interrupt-storm occurs when there is:

  1. Rapid link state changes / flaps.
  2. Due to bad signal received
  3. Due to excessive error being received.

The %ETH-4-ERRDISABLE: link-interrupt-storm error is triggered when the signal received on a port is extremely bad and the switch needs to work hard in order to understand it and process it.
This causes major burden on the CPU and in extreme cases can lead to the Forwarding Agent of the switch crashing which in turn leads to ASIC reinitialization. This would be equivalent with a soft restart.The link-interrupt-storm detection was implemented to avoid such a scenario and block the link and preventing any adverse effects on the rest of the switch.

This may be due to dirty fibre, bad patch panel or similar, bad transceiver or faulty device on the other end of the link.
The general recommendation is to perform a physical layer troubleshooting like cleaning the fiber, reseating / swapping the transceivers on both the ends one by one to see if the issue stopes.

However while the above is a general recommendation, you can open a case with us by writing an email to support@arista.com so that we shall be able to analyse the output of "show tech-support | no" and check why exactly is this issue happening.

Hope that helps.

Thanks,
Prajwala

 

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Posted by Alla Anunitya
Answered on July 17, 2020 7:27 am

Hi Brian,

Sometimes, the above issue is also caused due to the autoneg issues.  if autoneg is not resolving the link could flap many times a second and cause the protection mechanism to kick in.

Could you please paste the #show run int et30 output here.

In a similar case, I could see the same issue is resolved by using the following speed auto command. It is worth a try!

Seeing errdisabled link-interrupt-storm error with speed forced 1000full command under the interface config. Resolved when we used the speed auto 1000full command instead.

Let me know if this works.

Cheers.

Anunitya A

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