Catalyst 9300 burning through SFPs

[Haven]

I have a Catalyst 9300 switch that we purchased through a government contract roughly a year ago. Around the beginning of June this year, we had one of our users report that they'd lost connectivity on their machine. Troubleshooting eventually revealed that the fiber SFP (model GLC-SX-MM-RGD) had gone bad, and replacing it resolved the issue. Now, since then, this has happened four more times, all on different ports except for one where it's happened twice. Fiber SFPs aren't exactly cheap, so I was wondering if anyone else had experienced this issue and/or had a solution?

I've tried speaking to Cisco Support, but it turns out their warranty on the switch expired back in March. I'm still trying to track down the company we actually purchased from. Logs on the ports have not turned up anything noteworthy in any of these occurrences.

Any help on this would be appreciated, thanks.

[Reza Sharifi]

Hi,

Is this a fiber switch? I have never seen that many SFPs go bad. If I were to guess, this is some sort of hardware problem with the switch itself that causes the SFPs to go bad. Also, have you tried using a GLC-SX-MM (no RGD) and see if it makes a difference?

Optics are not expensive these days especially if the switch is not under any support contract. A good place to get them very cheap.

https://www.fs.com/?main_page=advanced_search_result&keyword=cisco%20glc-sx-mm&searchSubmit=Search

HTH

[Haven]

Rezi,

I haven't tried a different model SFP yet; not sure off hand if we have those available. This switch has just open SFP ports that accept fiber or copper SFPs; for the most part, we have been using fiber SFPs of the same model as mentioned above. Don't know if or how much that narrows things down.

[Reza Sharifi]

If you don't have any GLC-SX-MM handy, I think the easiest test is to get an SFP from the link I provided. They go for less than $10.

This way, you would know if the issue is the SFPs you are using or not.

HTH

[Leo Laohoo]

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@Haven wrote:

Troubleshooting eventually revealed that the fiber SFP (model GLC-SX-MM-RGD) had gone bad, and replacing it resolved the issue. Now, since then, this has happened four more times, all on different ports except for one where it's happened twice.

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Common denominator is the SFP are RGD.  What happens if ordinary GLC-SX-MM/GLC-SX-MMD were used? 

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@Haven wrote:

I've tried speaking to Cisco Support, but it turns out their warranty on the switch expired back in March. 

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No, that is incorrect.  Catalyst 9k switches are covered under Enhanced Limited Lifetime Hardware Warranty -- And this is FREE.

[Haven]

Leo,

Unfortunately I don't believe we have any of those on hand. The strange part is that the switch will see whenever one of these SFPs gets removed or installed. In looking to see if there was some way to "reset" the SFP, we ran a "show int trans det" on another Cisco switch with one of the bad SFPs installed. It showed under the "current" field that the SFP had 0.0 mA going to it, which tells me (and correct me if I'm wrong) that the SFP really is dead.

The good news is I was able to dig up the information on the vendor we purchased the switch from, so I will be going that route to get it replaced under warranty.

[Leo Laohoo]

What firmware is the switch running on?