'RTNETLINK answers: Invalid argument' after ifup ethX

On a device with Debian 10, I want to make a permanent change to the IP via modifying ***/etc/network/interfaces*** . Hence, I modify it as follows : auto lo iface lo inet loopback auto eth0 #iface eth0 inet dhcp iface eth0 inet static address 192.168.109.11 netmask 255.255.255.0 gateway 192.168.109.254 and after that I perform the following : ifdown eth0 && ifup eth0 but at this point it returns the following error : root@var-som-mx6:~# ifdown eth0 && ifup eth0 --verbose ifdown: interface eth0 not configured ifup: configuring interface eth0=eth0 (inet) /bin/run-parts --exit-on-error --verbose /etc/network/if-pre-up.d run-parts: executing /etc/network/if-pre-up.d/hostapd run-parts: executing /etc/network/if-pre-up.d/wpasupplicant /sbin/ip addr add 192.168.109.12/255.255.255.0 broadcast 192.168.109.255 dev eth0 label eth0 /sbin/ip link set dev eth0 up /sbin/ip route add default via 192.168.109.254 dev eth0 onlink RTNETLINK answers: Invalid argument ifup: failed to bring up eth0 ***ifconfig*** tells me the following : root@var-som-mx6:~# ifconfig eth0: flags=4163 mtu 1500 inet 192.168.109.11 netmask 255.255.255.0 broadcast 192.168.109.255 inet6 fe80::fadc:7aff:fe3e:8dbb prefixlen 64 scopeid 0x20 ether f8:dc:7a:3e:8d:bb txqueuelen 1000 (Ethernet) RX packets 35999 bytes 8217478 (7.8 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 5137 bytes 1559379 (1.4 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 lo: flags=73 mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10 loop txqueuelen 1 (Local Loopback) RX packets 2837 bytes 258173 (252.1 KiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 2837 bytes 258173 (252.1 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 What am I doing wrong?