Err disable Port

[gauravpundir231]

Hi All,

1 of my trunk port (access switch 3750) which is a uplink is going to err-disable state again & again. It has udld agg mode on.

On Core switch (cisco 6509) there is no udld config.

on same access switch other uplink is also configured with udld however it is not having any issues.i havent got any errors msgs.

My other access swictes are also configured with udld but none of them having issues.Please advise

[Leo Laohoo]

If the uplink is copper, then disable UDLD. If fibre optic, then investigate why the link is going into UDLD errors.

[gauravpundir231]

It is fiber uplink. I am not recevng any udld errors . Other uplinks are
cnfgured wth udld but not gettng err dsable mode.all are fibr uplink

[Leo Laohoo]

If its a fibre optic link, post the complete output to the following commands:
1. sh int status err (when the port goes into error disable again); and
2. sh interface <BLAH>

[gauravpundir231]

sry cant send the output as it is against company's policy.

On both interfaces there are no crc and any input errors.

pls let me know if you have other reasons for this or any troubleshooting steps

[Leo Laohoo]

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@gauravpundir231 wrote:

On both interfaces there are no crc and any input errors.

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Let us be the judge of that.

[chrihussey · Accepted solution]

Is logging enabled? (logging buffered debugging)

If the link is going err-disabled there should be something in the log indicating why it is happening. It should tell you if it is a UDLD thing or something else. This may help identify what is happening.

Then there is the physical piece. Replace fiber jumpers on either end and if possible move to new fiber pairs if applicable / possible. Could be a faulty GBIC or SFP on either end too.  I think these are the things to check and verify first before taking a deeper dive.

Finally, does it immediately go err-disabled, or does it run for a while before it happens? If the latter, is it somewhat at regular intervals, if so what is happening at that time data wise? What's the link utilization?

Just some things to look at. Hope this is of some help.

[gauravpundir231]

chrihussey

Thanks for the info.

We are going to change SFP and Fibr cable.