MX85 (and most likely the other new MX with the SFP/RJ45 combo ports for WAN) will it show the SFP?

Head in the Cloud

MX85 (and most likely the other new MX with the SFP/RJ45 combo ports for WAN) will it show the SFP?

The question is.

Will an MX85 show that there is an SFP inserted in the WAN port (without link on the SFP) ?
Just playing around with different SFP modules on WAN2 of a MX85 - nothing is connected to the RJ45 port, but documentation states that if an SFP is inserted, it should disable the RJ45 port.

Well , when we insert an SFP module in WAN2, it does not , eh "undisable" the WAN2 SFP, end do not disable the RJ45. Does the SFP module need to have link ? Or are we just using unsupported modules ?


Do anyone know ? 🙂




Meraki Employee
Meraki Employee

AFAIK and what I recall when I tested it was simply the presence of a SFP determines if the port is activated (and the corresponding copper port is disabled).

Head in the Cloud

I figured out why the SFP did not show up .... you ( read: "I" ) should really read the documentation carefully I guess (and Im still leaving my post here, because Im not embarrassed about when I make mistakes 🙂 ).


There this little "nugget" of gold information in the documentation:

"Detection of interface selection is done when the device is initializing. This takes place during boot up. If the preference is to use the SFP interfaces, then the SFP module must be inserted when the device is powered off. Please ensure your modules are properly inserted into the MX before boot up."


So this means, you cannot "hot enable" the SFP port on a MX85 (75 and 105) when you have booted it the first time without an SFP connected. Is this dumb ? - Yes .. I absolutely think so, and not the behaviour you "default" expect.

You can, as the documentation goes on to state, hotswap an SFP module thats connected at boot, if it fails, but not switch between SFP and RJ45 .. that is only done at boot..... *sigh*

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