Cisco 3560 showing 6000 input errors

Answered Question
Sep 24th, 2007

We have 2 3560 switches connected via fibre using 1000BaseLX sfp modules and fibre cable.

One of the switches is constantly having issues with thousands of input errors on the Gigabit Interface and reliability at 160-170/255.

The Cisco SDM also reports over 3700 oversize packets.

All the above within a 14 hour period.

The switch at the other end of the connection is not showing any errors at all.

Sometimes the problem switch loses connectivity altogether and we have had to move the Fibre module from one gi port to another to get it back working.

There are no errors on the actual fa ports, just the gi.

We have swapped out with another switch and other Fibre modules, but still getting the same issues.

One thing I would say is, that, the room the switch is located in is "broom cupboard" size, has 4 PC's in it aswell and no air conditioning...could this be causing this problem or is their a problem with the fibre?

I have this problem too.
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Correct Answer by Kevin Dorrell about 9 years 2 months ago

Gary,

Just a quick question. You say you have swapped out the switch and the SPF/GBIC module. That was presumably the switch that is showing the errors. But did you swap the SPF/GBIC at the other end? In my experience, problems are more often found at the transmitting end, even if it is the receiver that is counting the errors. Though this is more likely to be the case with the cheap SX modules than with the LX modules you are using.

Now I'll have a look at your console output.

Kevin Dorrell

Luxembourg

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Kevin Dorrell Tue, 09/25/2007 - 00:16

It could be a problem with the fiber. I doubt it is the environmental conditions, unless the room is unbearably hot.

Could you please post a show run int G0/x and a show int for each end of the fiber, as well as a show int G0/x counters detail for the bad end?

Kevin Dorrell

Luxembourg

garybeach Tue, 09/25/2007 - 00:47

Hi Kevin

I must admit I'm leaning towards a fibre issue, however, the fibre is not ours!

Here are the details requested.

Gary

Attachment: 
Correct Answer
Kevin Dorrell Tue, 09/25/2007 - 01:35

Gary,

Just a quick question. You say you have swapped out the switch and the SPF/GBIC module. That was presumably the switch that is showing the errors. But did you swap the SPF/GBIC at the other end? In my experience, problems are more often found at the transmitting end, even if it is the receiver that is counting the errors. Though this is more likely to be the case with the cheap SX modules than with the LX modules you are using.

Now I'll have a look at your console output.

Kevin Dorrell

Luxembourg

garybeach Tue, 09/25/2007 - 01:40

Kevin,

I must admit that we only concentrated at the end where the errors were occuring. We put in a new switch and purchased new fibre modules.

The very strange thing is that we have now moved the module three times, from one gi port to another (port fails) and then move it to another one. Very odd!

We didn't think to look at the other switch as that has never shown any errors. Might be worth a look though!

Cheers

Gary

glen.grant Tue, 09/25/2007 - 16:39

On the interface with the input errors are their any other type errors occuring , does anything show up with the "show int count errors " command for that interface ?

garybeach Wed, 09/26/2007 - 03:37

Hi Glen

I will try and get some info to you asap, but, at the moment, I am unable to connect to the switch as we have lost contact with it.

I am sending a guy on site to move the module into a different port again!!

Gary

garybeach Thu, 09/27/2007 - 02:27

Hi Kevin

We have managed to swap out the module at the transmitting end and, so far, we have not seen any errors at the remote switch!!

It's been clear of errors for over 19 hours now....so looking good.

Thanks very much for your advice.

Gary

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