Drivers for NIC (igb vs em)?

Yuri Pankov ypankov at
Wed Apr 29 17:46:17 UTC 2020

jester at wrote:
> This is (I think) a basic networking hardware question. I'm actually running FreeNAS 11.3, but I assume this relates to the underlying system.
> I have a motherboard with two built-in NICs. These appear as em0 and igb0. I'm just wondering why these are created with different drivers, instead of as em0 and em1 or igb0 and igb1. Is this something I have any control over?
> (I originally came to this question when I was considering using link aggregation with LACP, and it's recommended to do this only with the same NIC driver. I've subsequently decided not to do this, but remain curious about the underlying driver issue.)

The two were merged starting with FreeBSD 12.0 under the "em" name;  I 
don't know the exact historical reasons those were separate though.

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