OK, some more insight maybe.
Unlike what I thought (I did not remember) I have two NIC on that system.
It appears that either the NIC of the mainboard is broken or the driver has an
issue.
Currently I have deactivated the NIC of the mainboard and the problems went
away. Curiously that also made me have an issue with the monitor settings,
which I had to restore after a reboot.
The NIC now is running on the PCI-e version 1 short lane of the board.
As of now, the address is correctly acquired and the card works.
silversurfer:~ # lspci | egrep -i --color 'network|ethernet'
05:00.0 Ethernet controller: Intel Corporation 82574L Gigabit Network
Connection
which is now the working one.
06:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411
PCI Express Gigabit Ethernet Controller (rev 06)
which was the faulty / not working one.
# lshw -class network
*-network DISABLED
description: Ethernet interface
product: 82574L Gigabit Network Connection
vendor: Intel Corporation
physical id: 0
bus info: pci@0000:05:00.0
logical name: enp5s0
version: 00
serial: 68:05:ca:61:93:8f
capacity: 1Gbit/s
width: 32 bits
clock: 33MHz
capabilities: pm msi pciexpress msix bus_master cap_list rom ethernet
physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=e1000e
driverversion=5.15.7-1-default firmware=1.8-0 latency=0 link=no multicast=yes
port=twisted pair
resources: irq:49 memory:fe7c0000-fe7dffff memory:fe700000-fe77ffff
ioport:d000(size=32) memory:fe7e0000-fe7e3fff memory:fe780000-fe7bffff
*-network
description: Ethernet interface
product: RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
vendor: Realtek Semiconductor Co., Ltd.
physical id: 0
bus info: pci@0000:06:00.0
logical name: enp6s0
version: 06
serial: fc:aa:14:09:76:16
size: 1Gbit/s
capacity: 1Gbit/s
width: 64 bits
clock: 33MHz
capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet
physical tp mii 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
configuration: autonegotiation=on broadcast=yes driver=r8169
driverversion=5.15.7-1-default duplex=full firmware=rtl8168e-3_0.0.4 03/27/12
latency=0 link=yes multicast=yes port=twisted pair speed=1Gbit/s
resources: irq:53 ioport:c000(size=256) memory:fe600000-fe600fff
memory:d0000000-d0003fff
So enp6s0 was active the other (intel) was not when the problem occurred.
more info on it:
# ethtool enp6s0
Settings for enp6s0:
Supported ports: [ TP MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Half 1000baseT/Full
Supported pause frame use: Symmetric Receive-only
Supports auto-negotiation: Yes
Supported FEC modes: Not reported
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Half 1000baseT/Full
Advertised pause frame use: Symmetric Receive-only
Advertised auto-negotiation: Yes
Advertised FEC modes: Not reported
Link partner advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Link partner advertised pause frame use: No
Link partner advertised auto-negotiation: Yes
Link partner advertised FEC modes: Not reported
Speed: 1000Mb/s
Duplex: Full
Auto-negotiation: on
master-slave cfg: preferred slave
master-slave status: slave
Port: Twisted Pair
PHYAD: 0
Transceiver: external
MDI-X: Unknown
Supports Wake-on: pumbg
Wake-on: d
Link detected: yes
What was configured:
# ip a
1: lo: