External NIC with Qubes not working

User Support Hardware Issues
1

I have this card which is tested working with a Fedora 33 live USB, but does not work with Qubes on a Fedora 33 or Debian 10 netVM.

The card is attached successfully within Qubes, just as my on-board NIC’s are. The on-board NIC’s work normally when attached within Qubes, but not the external NIC. The card is recognized but can’t connect to any other host. If I set the IP manually I get a “Destination host unreachable” to my router.

This is an ASRock Z97 Mobo and when listing the card within the qubes-vm-settings it bears the same name as the on-board cards.

2

Do you see any entries in the logs for the qube where you have attached
the card?
You say that it is recognised - when you attach the cable do you see a
link up message?

3

When I pull out the cable I get “link down”. So something is happening.
DHCP doesn’t work but I can set the IP manually and the link up.
But I cannot ping my router or anything else.

Let me know if you need more info

4

this happen to me too so I open a shell and typed
$ dhcpclient

something I use to do in the old days ( did work got a IP )

5

@nozy I’ve had no luck with that command, unfortunately.

6

Linux dhclient command help and examples may help =)

7

Hi @unjust,

A DHCP configures the IP addresses, the DNS and consequently the IP route (and also a lot more…).

If you set a static IP (manually) setting, you must also check the route table. And if the route table isn’t correct you must set it manually (ip route add....).

I suggest that you read the very useful Archlinux Network Configuration with the iproute2 commands. This will help you to understand and diagnose yourself your network setting issue.

Note also that the Qubes OS uses NetworkManager and its applet for setting the network with a Graphical User Interface.

If finally you don’t understand what append, we’ll need some command outputs from you (nmcli, ip a, ip route, ping -c 1 <your router IP>, …).

8

I’ve ran through this a hundred times. I plug my cable into the integrated NIC and I get an IP instantly.
I copy that IP and routing configuration and manually input it after plugging in my external NIC, but I can’t get a connection to anything.

I’ve gone into the depths of nmcli as well, without any luck. Doing the same steps with my Fedora live USB works, so it seems to be a PCI virtualization issue.
@ludovic

9

Have you tried attaching the card with no-strict-rest=true and permissive=true? Sometimes one of these works. More details: PCI Devices | Qubes OS

10

Hi @unjust,

what about the @427F11FD0FAA4B080123 suggestion ?

Are you sure that your card is well recognized by the Linux kernel and the good driver loaded?

See the Device_driver section from ArchLinux Network (lspci -v, lspci -s <device id> -v, lsmod, kernel logs, …).

Can you provide us the vendor-id:device-id for this ethernet card? (I want to search your card in the linux-hardware.org database…)

11

This should be the one, two RJ45 ports from within sys-net:

00:07.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 0c)
Subsystem: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
Physical Slot: 7
Flags: bus master, fast devsel, latency 0, IRQ 70
I/O ports at c200 [size=256]
Memory at f2041000 (64-bit, non-prefetchable) [size=4K]
Memory at f2030000 (64-bit, prefetchable) [size=16K]
Capabilities: [40] Power Management version 3
Capabilities: [50] MSI: Enable+ Count=1/1 Maskable- 64bit+
Capabilities: [70] Express Endpoint, MSI 01
Capabilities: [d0] Vital Product Data
Kernel driver in use: r8169
Kernel modules: r8169

00:09.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 0c)
Subsystem: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
Physical Slot: 9
Flags: bus master, fast devsel, latency 0, IRQ 72
I/O ports at c400 [size=256]
Memory at f2043000 (64-bit, non-prefetchable) [size=4K]
Memory at f2038000 (64-bit, prefetchable) [size=16K]
Capabilities: [40] Power Management version 3
Capabilities: [50] MSI: Enable+ Count=1/1 Maskable- 64bit+
Capabilities: [70] Express Endpoint, MSI 01
Capabilities: [d0] Vital Product Data
Kernel driver in use: r8169
Kernel modules: r8169

More info from within dom0:

0e:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 0c)
Subsystem: Realtek Semiconductor Co., Ltd. Device 0123
Flags: bus master, fast devsel, latency 0, IRQ 17
I/O ports at 8000 [size=256]
Memory at ef600000 (64-bit, non-prefetchable) [size=4K]
Memory at e0400000 (64-bit, prefetchable) [size=16K]
Capabilities: [40] Power Management version 3
Capabilities: [50] MSI: Enable+ Count=1/1 Maskable- 64bit+
Capabilities: [70] Express Endpoint, MSI 01
Capabilities: [b0] MSI-X: Enable- Count=4 Masked-
Capabilities: [d0] Vital Product Data
Capabilities: [100] Advanced Error Reporting
Capabilities: [140] Virtual Channel
Capabilities: [160] Device Serial Number 01-00-00-00-68-4c-e0-00
Capabilities: [170] Latency Tolerance Reporting
Kernel driver in use: pciback
Kernel modules: r8169

0f:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 0c)
Subsystem: Realtek Semiconductor Co., Ltd. Device 0123
Flags: bus master, fast devsel, latency 0, IRQ 18
I/O ports at 7000 [size=256]
Memory at ef500000 (64-bit, non-prefetchable) [size=4K]
Memory at e0300000 (64-bit, prefetchable) [size=16K]
Capabilities: [40] Power Management version 3
Capabilities: [50] MSI: Enable+ Count=1/1 Maskable- 64bit+
Capabilities: [70] Express Endpoint, MSI 01
Capabilities: [b0] MSI-X: Enable- Count=4 Masked-
Capabilities: [d0] Vital Product Data
Capabilities: [100] Advanced Error Reporting
Capabilities: [140] Virtual Channel
Capabilities: [160] Device Serial Number 01-00-00-00-68-4c-e0-00
Capabilities: [170] Latency Tolerance Reporting
Kernel driver in use: pciback
Kernel modules: r8169

sys-net ~> lsmod

Module                  Size  Used by
nf_conntrack_netlink    57344  0
xt_nat                 16384  4
xen_netback            77824  2
rfkill                 32768  1
xt_REDIRECT            20480  1
ipt_REJECT             16384  2
nf_reject_ipv4         16384  1 ipt_REJECT
xt_state               16384  0
xt_conntrack           16384  4
nft_counter            16384  42
joydev                 28672  0
nft_chain_nat          16384  4
xt_MASQUERADE          20480  1
nf_nat                 57344  4 xt_nat,nft_chain_nat,xt_MASQUERADE,xt_REDIRECT
nf_conntrack          167936  7 xt_conntrack,nf_nat,xt_state,xt_nat,nf_conntrack_netlink,xt_MASQUERADE,xt_REDIRECT
nf_defrag_ipv6         24576  1 nf_conntrack
nf_defrag_ipv4         16384  1 nf_conntrack
nft_compat             20480  19
nf_tables             262144  121 nft_compat,nft_counter,nft_chain_nat
nfnetlink              20480  3 nft_compat,nf_conntrack_netlink,nf_tables
intel_rapl_msr         20480  0
intel_rapl_common      32768  1 intel_rapl_msr
crct10dif_pclmul       16384  1
crc32_pclmul           16384  0
crc32c_intel           24576  0
ghash_clmulni_intel    16384  0
snd_pcm               135168  0
snd_timer              49152  1 snd_pcm
snd                   110592  2 snd_timer,snd_pcm
soundcore              16384  1 snd
pcspkr                 16384  0
serio_raw              20480  0
ehci_pci               20480  0
ehci_hcd              110592  1 ehci_pci
r8169                 110592  0
e1000e                315392  0
ata_generic            16384  0
i2c_piix4              28672  0
pata_acpi              16384  0
floppy                 94208  0
drm_vram_helper        24576  0
drm_ttm_helper         16384  1 drm_vram_helper
ttm                   118784  2 drm_vram_helper,drm_ttm_helper
drm_kms_helper        282624  1 drm_vram_helper
cec                    61440  1 drm_kms_helper
drm                   638976  4 drm_kms_helper,drm_vram_helper,drm_ttm_helper,ttm
uinput                 20480  0
xen_privcmd            28672  42
xen_gntdev             28672  2
xen_gntalloc           20480  4
xen_blkback            57344  0
xen_evtchn             16384  5
bpf_preload            16384  0
ip_tables              36864  0
overlay               155648  1
xen_blkfront           57344  10

Vendor-id:device-id 10ec:8168

Working OOTB motherboard Ethernet connection, used presently:

00:08.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller (rev 11)
Subsystem: ASRock Incorporation Motherboard (one of many)
Physical Slot: 8
Flags: bus master, fast devsel, latency 0, IRQ 71
I/O ports at c300 [size=256]
Memory at f2042000 (64-bit, non-prefetchable) [size=4K]
Memory at f2034000 (64-bit, prefetchable) [size=16K]
Capabilities: [40] Power Management version 3
Capabilities: [50] MSI: Enable+ Count=1/1 Maskable- 64bit+
Capabilities: [70] Express Endpoint, MSI 01
Capabilities: [d0] Vital Product Data
Kernel driver in use: r8169
Kernel modules: r8169
12

Hi there,
please let me understand: when You set manually an ip, what kind of address did You set?
May your troubles be a fw blocking issue?
Cheers.

13

I set manually the same IP config I get when using the motherboard NIC, on the external one. Tested also other IP’s within the same network, but cannot get it working.
It works OOTB on bare metal live distros like Fedora 33, so I’m out of ideas here.

No firewalls should be blocking anything.

14

Hi there.
I’m sorry , but I think still have not understand correctly, so please, let me know:
fedora 33 and debian 10 tested with external device are AppVM or HVM, or what?
Thanks a lot…
:slight_smile:

15

Fedora running on my machine via a USB Live ISO manages to detect and handle my NIC correctly and smoothly (DHCP upon plugging in my cable).

With any Qubes HVM AppVM (Debian 10 , Fedora 33 both stock template) I can detect the card but have been unsuccessful with getting it to connect to anything. I am forced to input IP config manually, but cannot achieve a connection to the router or anything else when given that as gateway.
The logs in my previous posts is everything I could gather which should be relevant.

I know it’s a bit difficult to understand, find myself rearticulating this to make it more legible.
Thanks for hanging in there, and let me know if I need to clarify some more.

16

Hi there.
I think it’s really different, that’s why I asked.
With HVM You can try to assign pci device “directly” to HVM (as you can see there: PCI Devices | Qubes OS ) and cannot do the same with AppVM.
I think this test have to be the first You have to do, before “understand” better what’s happening…
Please, let me know.
Thanks.

17

Hi there.
I’m using sys-net, and it’s an HVM by default which is assigned all NIC’s Qubes can find, during the setup process.
They are all attached with --persistent and --no-strict-reset=True.
I’m at a loss for what to do next.

18

Hi there,
please can You report what’s in sys-net Settings from selected Devices?
Thanks a lot.

19

What is the output of:

  1. ip link [feel free to redact ethernet address after ‘link/ether’]
  2. ip addr [feel free to redact ethernet address after ‘link/ether’]
  3. ethtool [interface]
  4. sudo dmesg | grep -A3 r8169 [feel free to redact ethernet address from the first ‘r8169’ line]
  5. sudo dhclient -v -d -w [interface]
  6. sudo tcpdump -i [interface] -n arp or icmp & sleep 1; ping -c 1 [router-ip]; sudo killall tcpdump

If you are manually assigning an IP, don’t use the same IP as your internal NIC, change the last octet so there is no collision.

Ensure your router is not blocking new devices as well.

1 Like
20 
Devices attached to sys-net:
00:19.0 Ethernet controller: Intel Corporation Ethernet Connection (2) I218-V
00:07.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
0e:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller
0f:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller


~> ip l
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: ens6: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
    link/ether MOBO brd ff:ff:ff:ff:ff:ff
3: ens8: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
    link/ether ExtNIC brd ff:ff:ff:ff:ff:ff
4: ens9: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
    link/ether ExtNIC brd ff:ff:ff:ff:ff:ff
5: ens7: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
    link/ether MOBO brd ff:ff:ff:ff:ff:ff
6: vif7.0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 32
    link/ether fe:ff:ff:ff:ff:ff brd ff:ff:ff:ff:ff:ff

~> ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: ens6: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOW
N group default qlen 1000                                                           link/ether MOBO brd ff:ff:ff:ff:ff:ff
3: ens8: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOW
N group default qlen 1000                                                           link/ether ExtNIC brd ff:ff:ff:ff:ff:ff
4: ens9: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP gr
oup default qlen 1000                                                               link/ether ExtNIC brd ff:ff:ff:ff:ff:ff
5: ens7: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOW
N group default qlen 1000                                                           link/ether MOBO brd ff:ff:ff:ff:ff:ff
6: vif7.0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group de
fault qlen 32                                                                       link/ether fe:ff:ff:ff:ff:ff brd ff:ff:ff:ff:ff:ff
    inet 10.138.22.166/32 scope global vif7.0
       valid_lft forever preferred_lft forever
    inet6 fe80::fcff:ffff:feff:ffff/64 scope link        valid_lft forever preferred_lft forever


#plugged in connection below
~> sudo ethtool ens9
Settings for ens9:
        Supported ports: [ TP MII ]
        Supported link modes:   10baseT/Half 10baseT/Full 
                                100baseT/Half 100baseT/Full 
                                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/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: Symmetric        Link partner advertised auto-negotiation: Yes
        Link partner advertised FEC modes: Not reported
        Speed: 1000Mb/s
        Duplex: Full
        Port: Twisted Pair
        PHYAD: 0
        Transceiver: internal
        Auto-negotiation: on
        MDI-X: Unknown
        Supports Wake-on: pumbg
        Wake-on: d
        Link detected: yes

~> sudo ethtool ens8
Settings for ens8:
        Supported ports: [ TP MII ]
        Supported link modes:   10baseT/Half 10baseT/Full 
                                100baseT/Half 100baseT/Full 
                                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/Full 
        Advertised pause frame use: Symmetric Receive-only
        Advertised auto-negotiation: Yes
        Advertised FEC modes: Not reported
        Speed: Unknown!
        Duplex: Unknown! (255)
        Port: Twisted Pair
        PHYAD: 0
        Transceiver: internal
        Auto-negotiation: on
        MDI-X: Unknown
        Supports Wake-on: pumbg
        Wake-on: d
        Link detected: no

 ~> sudo dmesg | grep -A3 r8169
[    2.236697] libphy: r8169: probed
[    2.236859] r8169 0000:00:06.0 eth0: RTL8168g/8111g, MOBO, XID 4
c0, IRQ 88                                                                      [    2.236879] r8169 0000:00:06.0 eth0: jumbo features [frames: 9194 bytes, tx c
hecksumming: ko]                                                                [    2.237264] xen: --> pirq=17 -> irq=17 (gsi=17)
[    2.307543] Error: Driver 'pcspkr' is already registered, aborting...
[    2.327953] ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
--
[    2.376813] libphy: r8169: probed
[    2.376961] r8169 0000:00:08.0 eth1: RTL8168g/8111g, ExtNIC, XID 4
c0, IRQ 89                                                                      [    2.376982] r8169 0000:00:08.0 eth1: jumbo features [frames: 9194 bytes, tx c
hecksumming: ko]                                                                [    2.377728] xen: --> pirq=18 -> irq=21 (gsi=21)
[    2.388951] ehci-pci 0000:00:05.0: USB 2.0 started, EHCI 1.00
[    2.389422] libphy: r8169: probed
[    2.389582] r8169 0000:00:09.0 eth2: RTL8168g/8111g, ExtNIC, XID 4
c0, IRQ 90                                                                      [    2.389602] r8169 0000:00:09.0 eth2: jumbo features [frames: 9194 bytes, tx c
hecksumming: ko]                                                                [    2.402959] usb usb1: New USB device found, idVendor=1d6b, idProduct=0002, bc
dDevice= 5.12                                                                   [    2.402962] usb usb1: New USB device strings: Mfr=3, Product=2, SerialNumber=
1                                                                               [    2.402963] usb usb1: Product: EHCI Host Controller
--
[    2.618025] r8169 0000:00:08.0 ens8: renamed from eth1
[    2.625263] r8169 0000:00:09.0 ens9: renamed from eth2
[    2.633267] r8169 0000:00:06.0 ens6: renamed from eth0
[    2.638413] e1000e 0000:00:07.0 ens7: renamed from eth3
[    2.714704] usb 1-1: new high-speed USB device number 2 using ehci-pci
[    2.824485] r8169 0000:00:08.0: Direct firmware load for rtl_nic/rtl8168g-2.f
w failed with error -2                                                          [    2.824512] r8169 0000:00:08.0: Unable to load firmware rtl_nic/rtl8168g-2.fw
 (-2)                                                                           [    2.846097] Generic FE-GE Realtek PHY r8169-40:00: attached PHY driver (mii_b
us:phy_addr=r8169-40:00, irq=MAC)                                               [    2.866643] usb 1-1: New USB device found, idVendor=0627, idProduct=0001, bcd
Device= 0.00                                                                    [    2.866667] usb 1-1: New USB device strings: Mfr=1, Product=3, SerialNumber=1
0                                                                               [    2.866686] usb 1-1: Product: QEMU USB Tablet
--
[    2.929154] r8169 0000:00:08.0 ens8: No native access to PCI extended config 
space, falling back to CSI                                                      [    2.952476] r8169 0000:00:08.0 ens8: Link is Down
[    3.144792] r8169 0000:00:06.0: Direct firmware load for rtl_nic/rtl8168g-2.f
w failed with error -2                                                          [    3.144817] r8169 0000:00:06.0: Unable to load firmware rtl_nic/rtl8168g-2.fw
 (-2)                                                                           [    3.170311] Generic FE-GE Realtek PHY r8169-30:00: attached PHY driver (mii_bus:phy_addr=r8169-30:00, irq=MAC)
[    3.278116] r8169 0000:00:09.0: Direct firmware load for rtl_nic/rtl8168g-2.f
w failed with error -2                                                          [    3.278140] r8169 0000:00:09.0: Unable to load firmware rtl_nic/rtl8168g-2.fw
 (-2)                                                                           [    3.278243] r8169 0000:00:06.0 ens6: Link is Down
[    3.300105] Generic FE-GE Realtek PHY r8169-48:00: attached PHY driver (mii_b
us:phy_addr=r8169-48:00, irq=MAC)                                               [    3.408244] r8169 0000:00:09.0 ens9: Link is Down
[    6.251657] r8169 0000:00:06.0 ens6: Link is Up - 1Gbps/Full - flow control r
x/tx                                                                            [    6.251684] IPv6: ADDRCONF(NETDEV_CHANGE): ens6: link becomes ready
[   10.091960] vif vif-7-0 vif7.0: Guest Rx ready
[   10.091985] IPv6: ADDRCONF(NETDEV_CHANGE): vif7.0: link becomes ready
[70937.614564] r8169 0000:00:06.0 ens6: Link is Down
[157233.059724] r8169 0000:00:09.0 ens9: Link is Up - 1Gbps/Full - flow control 
rx/tx                                                                           [157233.059759] IPv6: ADDRCONF(NETDEV_CHANGE): ens9: link becomes ready
[157238.149126] ------------[ cut here ]------------
[157238.149166] NETDEV WATCHDOG: ens9 (r8169): transmit queue 0 timed out
[157238.149209] WARNING: CPU: 1 PID: 0 at net/sched/sch_generic.c:467 dev_watchd
og+0x24d/0x260                                                                  [157238.149248] Modules linked in: nf_conntrack_netlink xt_nat xen_netback joydev rfkill xt_REDIRECT ipt_REJECT nf_reject_ipv4 intel_rapl_msr intel_rapl_common 
xt_state crct10dif_pclmul crc32_pclmul crc32c_intel xt_conntrack nft_counter ghash_clmulni_intel drm_vram_helper nft_chain_nat drm_ttm_helper ttm xt_MASQUERADE nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nft_compat nf_tables drm_kms_helper nfnetlink ehci_pci cec ehci_hcd snd_pcm snd_timer drm snd soundcore e1000e pcspkr r8169 serio_raw ata_generic i2c_piix4 pata_acpi floppy uinput xen_privcmd xen_gntdev xen_gntalloc xen_blkback xen_evtchn bpf_preload ip_tables overlay xen_blkfront                                                                     [157238.150350] CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.12.14-1.fc32.qubes.x
86_64 #1                                                                        [157238.150384] Hardware name: Xen HVM domU, BIOS 4.14.2 07/09/2021
[157238.150415] RIP: 0010:dev_watchdog+0x24d/0x260
--
[158203.283291] r8169 0000:00:09.0 ens9: rtl_rxtx_empty_cond == 0 (loop: 42, del
ay: 100).                                                                       

 ~> sudo dhclient -v -d -w ens9
Internet Systems Consortium DHCP Client 4.4.1
Copyright 2004-2018 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Listening on LPF/ens9/ExtNIC
Sending on   LPF/ens9/ExtNIC
Sending on   Socket/fallback
DHCPDISCOVER on ens9 to 255.255.255.255 port 67 interval 8
DHCPDISCOVER on ens9 to 255.255.255.255 port 67 interval 11


~> sudo tcpdump -i ens9 -n arp or icmp & sleep 1; ping -c 1 #RouterIP; sudo ki
llall tcpdump                                                                   tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on ens9, link-type EN10MB (Ethernet), capture size 262144 bytes
connect: Network is unreachable

0 packets captured
0 packets received by filter
0 packets dropped by kernel
Job 1, 'sudo tcpdump -i ens9 -n arp or…' has ended

I see one line of interest:
Direct firmware load for rtl_nic/rtl8168g-2.fw failed with error -2

Searching for that error message leads me to the same place as last time, when I tried to download that firmware, which is non-free.
https://packages.debian.org/buster/firmware-realtek
It shouldn’t be necessary as it works out of the box on a Fedora Live USB. Fedora explicitly disallows installation of non-free software.
Besides, it didn’t help me with my connection, it just removed that error message.
Probably works on a Debian-based distro as well, I could try it.