I recently setup a Debian 11.2 system on a Gigabyte B660M D3H DDR4. During installation I noticed the onboard networking didn't function.
james@debian11:~$ lspci |grep Ethernet
04:00.0 Ethernet controller: Intel Corporation Ethernet Controller I225-V (rev 03)
With the default 5.10 kernel the module 'igc' for this controller fails with the following error:
root@debian11:/var/log# grep igc messages
Feb 25 09:44:13 debian11 kernel: [ 4.353002] igc: probe of 0000:03:00.0 failed with error -2
The solution for me was to install kernel 5.15 from backports:
root@debian11:/var/log# uname -a
Linux debian11 5.15.0-0.bpo.3-amd64 #1 SMP Debian 5.15.15-2~bpo11+1 (2022-02-03) x86_64 GNU/Linux
root@debian11:/var/log# dmesg |grep igc
[ 3.825490] igc 0000:04:00.0: PTM enabled, 4ns granularity
[ 3.871312] igc 0000:04:00.0 (unnamed net_device) (uninitialized): PHC added
[ 3.930345] igc 0000:04:00.0: 4.000 Gb/s available PCIe bandwidth (5.0 GT/s PCIe x1 link)
[ 3.930348] igc 0000:04:00.0 eth0: MAC: d8:5e:d3:91:15:95
[ 3.931844] igc 0000:04:00.0 enp4s0: renamed from eth0
[ 10.465411] igc 0000:04:00.0 enp4s0: NIC Link is Up 1000 Mbps Full Duplex, Flow Control: RX/TX
You'll temporarily need an alternative network controller to install and update the system. I used a USB adapter that I have on hand for such problems.
