Linux, SFP Modules vs SFP Cage

This maybe a simple question, but I can’t seem to find an answer out there for it. When using SFPs on a linux machine, does the device name (e.g eth0) follow the SFP module of the SFP cage?

In other words if I have an 1Gb SFP in the cage, and it is called eth0, if I remove that module and replace it with an 10Gb SFP+ module, will that interface still be called eth0 and therefore all my network settings will apply to the new module?

My specific use case is that I am setting up a new Smoothwall server on my bench and using a copper SFP module for this, but when I put the server into production it will be using a 10Gb Fiber SFP+ module. I would like to know if I have to plan on completely re-configuring the network or not when I do this.

Asked By: JRC


The configuration will follow the "cage" (the network interface). SFP modules aren’t entirely dumb, but for this purpose you can consider them interchangeable.

Answered By: pericynthion
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