Unable to set SFP+ Port to Auto Negotiate

[letakhar]

We have multiple MS4300-28G switches and on 3 of them we are unable to set port 1/0/27 SFP+ to Auto Negotiate,

We have a 10G SFP+ module connected and we need to be able to connect this to a 10G device and then swap it over to a 1G device.

When trying via the console all i get is an error 'Invalid physical mode for this port'

I have tried all different scenarios with the cable connected to disconnected and SFP+ module unplugged.

Any help will be very appreciated.

[letakhar · Accepted solution]

Thank you for all your help but I have found the solution to my issue

It seems that we have SFP+ modules from FS.com that are different revision numbers.

As such the Revision A modules are compatible with 10G-SR/1000SX thus when we plug in a 1GB media converter when the switch port is set to 10G it drops down to 1G and then allows us to plug in our test unit at 10G and the link is then at 10G. and the modules that don't have a revision or are labeled as revision B do not work in the same way

Im assuming that it is mainly due to the 1000SX compatibility.

 Thank you

[schumaku]

What kind of SFP+ module is plugged? While an SFP+ RJ45 module allows to auto-adopt on different link speeds, there is no such feature available in the industry doing link speed negotiation on fiber ports and fiber links.

[letakhar]

We have tried a couple of different SFP+ modules.

Currently using a FS.com SFP-10GSR-85 850nm

But have also tried a gbics 10GBASE-SR SFP+ 850nm

and a few others but all 10G SR 850nm

It just seems odd that we have one switch that is working perfectly fine with the same FS.com SFP+ modules but even with a copy of the switch config this is not working on the others.

There is one thing that I can think of but i wouldn't assume that it would change much is that the one working switch is non-Poe and the other 3 are the Poe version.

Regards

[letakhar]

Sorry just to clarify we are not using RJ45 modules, just Fiber.

[top_of_rack_var]

What @schumaku said... most 10G optic modules will only operate at 10 gig link speeds, so the ports cant be set to auto while they're installed.  I'm pretty sure though if the user will replace with a 1G module, that the port will auto-switch to the 1 gig link speed when it's inserted.

If that's not what you're planning/hoping to do, can you elaborate?  Is it the _other_ end that you plan on switching?

[schumaku]

While an SFP+ RJ45 module allows to auto-adopt on different link speeds, there is no such feature available in the industry doing link speed negotiation on fiber ports and fiber links. Random side effect on your modules?

[letakhar · Accepted solution]

Thank you for all your help but I have found the solution to my issue

It seems that we have SFP+ modules from FS.com that are different revision numbers.

As such the Revision A modules are compatible with 10G-SR/1000SX thus when we plug in a 1GB media converter when the switch port is set to 10G it drops down to 1G and then allows us to plug in our test unit at 10G and the link is then at 10G. and the modules that don't have a revision or are labeled as revision B do not work in the same way

Im assuming that it is mainly due to the 1000SX compatibility.

 Thank you