Drivers for NIC (igb vs em)?

Polytropon freebsd at
Thu Apr 30 03:42:36 UTC 2020

On Wed, 29 Apr 2020 20:46:14 +0300, Yuri Pankov wrote:
> 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.
> [...]
> 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.

Technically, em is the older driver (Intel PRO/1000 family
of Gigabit chipsets), and igb introduced support for the
newer models (Intel Gigabit ET/VT Dual Port Server Adapter

On FreeBSD 11 (FreeNAS 11.3), there's still a manual entry for
igb and em, listing different hardware. I'mm sure there are
many similarities, so igb got integrated / merged with em, as
on FreeBSD 12, there no longer is "man 4 igb", even though a
file /boot/kernel/if_igb.ko still exists (12.0-p7 experimental
system here).

For comparison:

FreeBSD 11.3 "man 4 igb":

FreeBSD 11.3 "man 4 em":

FreeBSD 12.1 "man 4 em":

The "em" manual page has been updated.

Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...

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