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Date:      Thu, 30 Apr 2020 05:30:03 +0200
From:      Polytropon <>
Subject:   Re: Drivers for NIC (igb vs em)?
Message-ID:  <>
In-Reply-To: <>
References:  <>

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On Wed, 29 Apr 2020 12:52:35 -0400, wrote:
> 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?

Unlike Linux, where network devices are typically enumerated
depending on the order they are detected in, FreeBSD uses a
device name according to the hardware found.

The diver manuals ("man 4 <name>") state:

em - Intel(R) PRO/1000 Gigabit Ethernet adapter driver

igb - Intel(R) PRO/1000 PCI Express Gigabit Ethernet adapter driver

So your mainboard has two _different_ kinds of networking hardware
installed, that's why FreeBSD loads the appropriate driver for each
one, leading to different names.

> If it's relevant, the output of lspci for the Ethernet controllers only:
> $ sudo lspci -v
> [...]
> 00:1f.6 Ethernet controller: Intel Corporation Ethernet Connection (2) I219-LM (rev 31)
>         Subsystem: ASRock Incorporation Device 15b7
>         Flags: bus master, fast devsel, latency 0, IRQ 16
>         Memory at df100000 (32-bit, non-prefetchable)
>         Capabilities: [c8] Power Management version 3
>         Capabilities: [d0] MSI: Enable+ Count=1/1 Maskable- 64bit+
>         Capabilities: [e0] PCI Advanced Features
> 02:00.0 Ethernet controller: Intel Corporation I210 Gigabit Network Connection (rev 03)
>         Subsystem: ASRock Incorporation Device 1533
>         Flags: bus master, fast devsel, latency 0, IRQ 19
>         Memory at df000000 (32-bit, non-prefetchable)
>         I/O ports at e000
>         Memory at df080000 (32-bit, non-prefetchable)
>         Capabilities: [40] Power Management version 3
>         Capabilities: [50] MSI: Enable- Count=1/1 Maskable+ 64bit+
>         Capabilities: [70] MSI-X: Enable+ Count=5 Masked-
>         Capabilities: [a0] Express Endpoint, MSI 00
>         Capabilities: [100] Advanced Error Reporting
>         Capabilities: [140] Device Serial Number d0-50-99-ff-ff-c1-f6-ab
>         Capabilities: [1a0] Transaction Processing Hints

As you can see from the 1st line of each entry, lspci confirms
that you're dealing with two different models (both made by
Intel, though).

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

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