The journal clearly shows that ifup did get started:
Jun 19 13:49:08 lam-wily6401 systemd[1]: Starting ifup for eth0...
[...]
Jun 19 13:49:08 lam-wily6401 ifup[456]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3 (xid=0x15a1af31)
Jun 19 13:49:08 lam-wily6401 dhclient[488]: DHCPREQUEST of 192.168.2.189 on eth0 to 255.255.255.255 port 67 (xid=0x31afa115)
Jun 19 13:49:08 lam-wily6401 dhclient[488]: DHCPOFFER of 192.168.2.189 from 192.168.2.1
Jun 19 13:49:08 lam-wily6401 ifup[456]: DHCPREQUEST of 192.168.2.189 on eth0 to 255.255.255.255 port 67 (xid=0x31afa115)
Jun 19 13:49:08 lam-wily6401 ifup[456]: DHCPOFFER of 192.168.2.189 from 192.168.2.1
[...]
Jun 19 13:49:09 lam-wily6401 dhclient[488]: DHCPACK of 192.168.2.189 from 192.168.2.1
Jun 19 13:49:09 lam-wily6401 ifup[456]: DHCPACK of 192.168.2.189 from 192.168.2.1
Jun 19 13:49:09 lam-wily6401 dhclient[488]: bound to 192.168.2.189 -- renewal in 297 seconds.
Jun 19 13:49:09 lam-wily6401 ifup[456]: bound to 192.168.2.189 -- renewal in 297 seconds.
Jun 19 13:49:09 lam-wily6401 ifquery[748]: eth0=eth0
Jun 19 13:49:09 lam-wily6401 systemd[1]: Started ifup for eth0.
So I'm a bit confused what's wrong now. Can you please copy&paste the output of "sudo systemctl status -s ifup@eth0"?
The journal clearly shows that ifup did get started:
Jun 19 13:49:08 lam-wily6401 systemd[1]: Starting ifup for eth0...
[...]
Jun 19 13:49:08 lam-wily6401 ifup[456]: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3 (xid=0x15a1af31)
Jun 19 13:49:08 lam-wily6401 dhclient[488]: DHCPREQUEST of 192.168.2.189 on eth0 to 255.255.255.255 port 67 (xid=0x31afa115)
Jun 19 13:49:08 lam-wily6401 dhclient[488]: DHCPOFFER of 192.168.2.189 from 192.168.2.1
Jun 19 13:49:08 lam-wily6401 ifup[456]: DHCPREQUEST of 192.168.2.189 on eth0 to 255.255.255.255 port 67 (xid=0x31afa115)
Jun 19 13:49:08 lam-wily6401 ifup[456]: DHCPOFFER of 192.168.2.189 from 192.168.2.1
[...]
Jun 19 13:49:09 lam-wily6401 dhclient[488]: DHCPACK of 192.168.2.189 from 192.168.2.1
Jun 19 13:49:09 lam-wily6401 ifup[456]: DHCPACK of 192.168.2.189 from 192.168.2.1
Jun 19 13:49:09 lam-wily6401 dhclient[488]: bound to 192.168.2.189 -- renewal in 297 seconds.
Jun 19 13:49:09 lam-wily6401 ifup[456]: bound to 192.168.2.189 -- renewal in 297 seconds.
Jun 19 13:49:09 lam-wily6401 ifquery[748]: eth0=eth0
Jun 19 13:49:09 lam-wily6401 systemd[1]: Started ifup for eth0.
So I'm a bit confused what's wrong now. Can you please copy&paste the output of "sudo systemctl status -s ifup@eth0"?