The last error is on my side but not know exactly what is the problem for the moment so sorry.
I try on a third computer same error but finally use another vlan and catch IP directly.

Something can intercept/block RX packet from a working usb/ethernet device fo reach the kernel ?

The DHCP set up is done by a dhcp client program, and not "the kernel". That dhcp program is typically run by a network management subsystem.

Which network managment are you using?

What's the output of pgrep -a dhcp ?

Do you have a firewall set up?

Now I can have this error in the log with the latest driver from Realtek (2.14) :
r8152: module verification failed: signature and/or required key missing - tainting kernel (This parameter change nothing in MakeFile : CONFIG_MODULE_SIG=n)

With kernel 5.10 delivered driver no error the firmware is loaded successfully but seem not received/accept ip from the DHCP server.

Something can intercept/block RX packet from a working usb/ethernet device fo reach the kernel ?
tcpdump of this interface show me the packet so the physical device received really the packet just seem not forwarded to the kernel that's possible ?

also what does /etc/network/interfaces file look like?

auto eth0
iface eth0 inet dhcp

I'm with root

I try that now
Thank you

Sorry for this bug but it's very strange. I upgrade my kernel to the latest 5.10 from Chimaera but seem the exact same issue.
Integrated driver load the firmware without issue but same problem
Compiled driver from Realtek website not load firmware but same problem again

When I fix the static ip address tcpdump view the ping query AND ping reply but nothing come back to the console (no error, no ping).
I try the quirk way now may be it's that

That's not a good idea and anyway it would be reverted at the next boot.

The r8152 driver is included in the stock beowulf kernel so the OP should try applying the quirk mentioned in the bug report linked by PedroReina.

perhaps like this...

lsusb
#Bus 003 Device 002: ID 0bda:8771 Realtek Semiconductor Corp.
chown -R glenn:glenn /dev/bus/usb/003/002

not the symbol, it was "demsg" instead of dmesg.

LOL!  May be time for me to get those cataracts removed.

dice wrote:

head on a stick made a typo.

I'm not seeing it.  # signifies root in a terminal.  He just used the symbol instead of the words.

not the symbol, it was "demsg" instead of dmesg.

head on a stick made a typo.

I'm not seeing it.  # signifies root in a terminal.  He just used the symbol instead of the words.

as root user,

dmesg | grep firmware

also what does /etc/network/interfaces file look like?

Did you check if the firmware was loaded?

# demsg | grep firmware

It not try to load any firmware and no "firmware" entry with modinfo r8152
How I can force a firmware ?
Kernel 5.X trying to load "rtl_nic/rtl8153b-2.fw"

Already done but not work

# demsg | grep firmware

Can you assign static IP addresses manually? For example

# ip a add 192.168.0.23/24 dev eth0
# ip r add default via 192.168.0.1

Also check your router settings, my old router ran out of DHCP slots after I was running a randomised MAC address on my laptop for a while.

Try the firmware-realtek package from the beowulf-backports repository.

Thank you for idea but not seem work better with backports and even chimaera
firmware-realtek                                            20201118-1