/etc/network/interfaces                                                                                                                                             
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet dhcp

freeartist@devuan:~$ sudo su
[sudo] password for freeartist: 
root@devuan:/home/freeartist# 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: eth0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc fq_codel state DOWN group default qlen 1000
    link/ether 00:1d:7d:c7:be:43 brd ff:ff:ff:ff:ff:ff
root@devuan:/home/freeartist# ifdown eth0
Killed old client process
Internet Systems Consortium DHCP Client 4.4.3
Copyright 2004-2022 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Listening on LPF/eth0/00:1d:7d:c7:be:43
Sending on   LPF/eth0/00:1d:7d:c7:be:43
Sending on   Socket/fallback
DHCPRELEASE of 192.168.0.20 on eth0 to 192.168.0.1 port 67
send_packet: Network is unreachable
send_packet: please consult README file regarding broadcast address.
dhclient.c:3124: Failed to send 300 byte long packet over fallback interface.
root@devuan:/home/freeartist# ifup eth0
Internet Systems Consortium DHCP Client 4.4.3
Copyright 2004-2022 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Listening on LPF/eth0/00:1d:7d:c7:be:43
Sending on   LPF/eth0/00:1d:7d:c7:be:43
Sending on   Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 7
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 13
DHCPOFFER of 192.168.0.20 from 192.168.0.1
DHCPREQUEST for 192.168.0.20 on eth0 to 255.255.255.255 port 67
DHCPACK of 192.168.0.20 from 192.168.0.1
bound to 192.168.0.20 -- renewal in 238 seconds.
root@devuan:/home/freeartist# 

root@devuan:/etc/network# sudo /etc/init.d/networking restart
Running /etc/init.d/networking restart is deprecated because it may not re-enable some interfaces ... (warning).
Reconfiguring network interfaces...Killed old client process
Internet Systems Consortium DHCP Client 4.4.3
Copyright 2004-2022 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Listening on LPF/eth0/00:1d:7d:c7:be:43
Sending on   LPF/eth0/00:1d:7d:c7:be:43
Sending on   Socket/fallback
DHCPRELEASE of 192.168.0.20 on eth0 to 192.168.0.1 port 67
Internet Systems Consortium DHCP Client 4.4.3
Copyright 2004-2022 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/

Listening on LPF/eth0/00:1d:7d:c7:be:43
Sending on   LPF/eth0/00:1d:7d:c7:be:43
Sending on   Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 6
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 13
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 11
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 11
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 17
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3
No DHCPOFFERS received.
No working leases in persistent database - sleeping.
done.
root@devuan:/etc/network#