Posted on December 16, 2020 4:26 am
 |  Asked by Christopher
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We have a couple 1G TX SFPs installed in a 7280SR2K-48C6 in the 1/10G ports, not the 25G ports, and even when no cable is connected to the SFP, the link on the switch is still up.  If we connect a cable to it, it works as normal, but removing the cable the link never goes down.  This also means that MAC address tables don’t immediately clear as it thinks the interface is still up.  Is this normal?  I’ve not been able to find any documentation about this.

Posted by Aniket Bhowmick
Answered on December 16, 2020 4:42 am

Hi Christopher,

This is not normal, the link should go down when cable is removed which should trigger the mac address table flush.

We have seen similar issues for few other platforms but not for 7280SR2K-48C6. I couldn't find any such issue related to this platform.

I suggest if you can open a case with TAC by sending an email to



Posted by Kenneth Finnegan
Answered on December 16, 2020 4:51 pm

Are these with Arista branded baseT transceivers or third-party? Some brands of baseT SFP transceivers are notorious for not correctly using the LOS pin to signal to the switch when the PHY goes down.

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