--------------- Tests on Focal: --------------- root@focal-1:~# cat /etc/systemd/network/10-netplan-enp7s0.network [Match] Name=enp7s0 [Address] Address=169.254.240.10/24 DuplicateAddressDetection=ipv4 root@focal-1:~# netplan apply root@focal-1:~# journalctl -b -u systemd-networkd --no-pager -o short-precise | grep -i ACD Mar 10 14:24:37.915226 focal-1 systemd-networkd[1863]: enp7s0: Starting IPv4ACD client. Probing address 169.254.240.10 Mar 10 14:24:38.454594 focal-1 systemd-networkd[1863]: IPV4ACD: Probing 169.254.240.10 Mar 10 14:24:38.455467 focal-1 systemd-networkd[1863]: IPV4ACD: Conflict on 169.254.240.10 (1) Mar 10 14:24:38.458219 focal-1 systemd-networkd[1863]: IPV4ACD: STOPPED Mar 10 14:24:38.458267 focal-1 systemd-networkd[1863]: enp7s0: Stopping ACD client... Mar 10 14:24:50.941389 focal-1 systemd-networkd[1863]: IPV4ACD: STOPPED Mar 10 14:24:50.941398 focal-1 systemd-networkd[1863]: enp7s0: Stopping ACD client... Mar 10 14:24:51.140643 focal-1 systemd-networkd[1925]: enp7s0: Starting IPv4ACD client. Probing address 169.254.240.10 Mar 10 14:24:51.454399 focal-1 systemd-networkd[1925]: IPV4ACD: Probing 169.254.240.10 Mar 10 14:24:51.455156 focal-1 systemd-networkd[1925]: IPV4ACD: Conflict on 169.254.240.10 (1) Mar 10 14:24:51.455491 focal-1 systemd-networkd[1925]: IPV4ACD: STOPPED Mar 10 14:24:51.455510 focal-1 systemd-networkd[1925]: enp7s0: Stopping ACD client... root@focal-1:~# vi /etc/systemd/network/10-netplan-enp7s0.network root@focal-1:~# cat /etc/systemd/network/10-netplan-enp7s0.network [Match] Name=enp7s0 [Address] Address=169.254.240.10/24 DuplicateAddressDetection=none root@focal-1:~# netplan apply root@focal-1:~# journalctl -b -u systemd-networkd --no-pager -o short-precise | grep -i ACD Mar 10 14:24:37.915226 focal-1 systemd-networkd[1863]: enp7s0: Starting IPv4ACD client. Probing address 169.254.240.10 Mar 10 14:24:38.454594 focal-1 systemd-networkd[1863]: IPV4ACD: Probing 169.254.240.10 Mar 10 14:24:38.455467 focal-1 systemd-networkd[1863]: IPV4ACD: Conflict on 169.254.240.10 (1) Mar 10 14:24:38.458219 focal-1 systemd-networkd[1863]: IPV4ACD: STOPPED Mar 10 14:24:38.458267 focal-1 systemd-networkd[1863]: enp7s0: Stopping ACD client... Mar 10 14:24:50.941389 focal-1 systemd-networkd[1863]: IPV4ACD: STOPPED Mar 10 14:24:50.941398 focal-1 systemd-networkd[1863]: enp7s0: Stopping ACD client... Mar 10 14:24:51.140643 focal-1 systemd-networkd[1925]: enp7s0: Starting IPv4ACD client. Probing address 169.254.240.10 Mar 10 14:24:51.454399 focal-1 systemd-networkd[1925]: IPV4ACD: Probing 169.254.240.10 Mar 10 14:24:51.455156 focal-1 systemd-networkd[1925]: IPV4ACD: Conflict on 169.254.240.10 (1) Mar 10 14:24:51.455491 focal-1 systemd-networkd[1925]: IPV4ACD: STOPPED Mar 10 14:24:51.455510 focal-1 systemd-networkd[1925]: enp7s0: Stopping ACD client... Mar 10 14:25:14.611042 focal-1 systemd-networkd[1925]: IPV4ACD: STOPPED Mar 10 14:25:14.611048 focal-1 systemd-networkd[1925]: enp7s0: Stopping ACD client... root@focal-1:~# --------------- Tests on Jammy: --------------- ubuntu@jammy-2:~$ cat /etc/systemd/network/10-netplan-ens8.network [Match] Name=ens8 [Address] Address=169.254.241.10/24 DuplicateAddressDetection=none ubuntu@jammy-2:~$ networkctl status ens8 --no-pager ● 3: ens8 Link File: /usr/lib/systemd/network/99-default.link Network File: /etc/systemd/network/10-netplan-ens8.network Type: ether State: routable (configured) Online state: online Alternative Names: enp0s8 Path: pci-0000:00:08.0 Driver: virtio_net Vendor: Red Hat, Inc. Model: Virtio network device HW Address: 52:54:00:ee:01:d1 MTU: 1500 (min: 68, max: 65535) QDisc: fq_codel IPv6 Address Generation Mode: eui64 Queue Length (Tx/Rx): 1/1 Auto negotiation: no Speed: n/a Address: 169.254.241.10 fe80::5054:ff:feee:1d1 Activation Policy: up Required For Online: yes DHCP6 Client DUID: DUID-EN/Vendor:0000ab117b40e8a688053bff0000 ubuntu@jammy-2:~$ sudo netplan apply ubuntu@jammy-2:~$ journalctl -b -u systemd-networkd --no-pager -o short-precise | grep -i ACD Mar 10 14:55:44.903842 jammy-2 systemd-networkd[3102]: /etc/systemd/network/10-netplan-ens8.network: An IPv4 link-local address is specified, enabling IPv4 Address Conflict Detection (ACD). Mar 10 14:55:44.948006 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: running -> init Mar 10 14:55:44.948009 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: STOPPED Mar 10 14:55:44.948014 jammy-2 systemd-networkd[3102]: ens8: Removing address 169.254.241.10, as the ACD client is stopped. Mar 10 14:55:44.952076 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: init -> started Mar 10 14:55:44.956764 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: started -> waiting-probe Mar 10 14:55:44.956905 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: waiting-probe -> init Mar 10 14:55:44.987725 jammy-2 systemd-networkd[3102]: ens8: Configuring IPv4ACD for address 169.254.241.10 Mar 10 14:55:44.990847 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: init -> started Mar 10 14:55:44.990867 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: started -> waiting-probe Mar 10 14:55:45.359288 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: Probing 169.254.241.10 Mar 10 14:55:45.359461 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: waiting-probe -> probing Mar 10 14:55:46.859095 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: Probing 169.254.241.10 Mar 10 14:55:48.359157 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: Probing 169.254.241.10 Mar 10 14:55:48.359486 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: probing -> waiting-announce ubuntu@jammy-2:~$ sudo vi /etc/systemd/network/10-netplan-ens8.network ubuntu@jammy-2:~$ cat /etc/systemd/network/10-netplan-ens8.network [Match] Name=ens8 [Address] Address=169.254.241.10/24 DuplicateAddressDetection=ipv4 ubuntu@jammy-2:~$ sudo netplan apply ubuntu@jammy-2:~$ journalctl -b -u systemd-networkd --no-pager -o short-precise | grep -i ACD Mar 10 14:55:44.903842 jammy-2 systemd-networkd[3102]: /etc/systemd/network/10-netplan-ens8.network: An IPv4 link-local address is specified, enabling IPv4 Address Conflict Detection (ACD). Mar 10 14:55:44.948006 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: running -> init Mar 10 14:55:44.948009 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: STOPPED Mar 10 14:55:44.948014 jammy-2 systemd-networkd[3102]: ens8: Removing address 169.254.241.10, as the ACD client is stopped. Mar 10 14:55:44.952076 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: init -> started Mar 10 14:55:44.956764 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: started -> waiting-probe Mar 10 14:55:44.956905 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: waiting-probe -> init Mar 10 14:55:44.987725 jammy-2 systemd-networkd[3102]: ens8: Configuring IPv4ACD for address 169.254.241.10 Mar 10 14:55:44.990847 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: init -> started Mar 10 14:55:44.990867 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: started -> waiting-probe Mar 10 14:55:45.359288 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: Probing 169.254.241.10 Mar 10 14:55:45.359461 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: waiting-probe -> probing Mar 10 14:55:46.859095 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: Probing 169.254.241.10 Mar 10 14:55:48.359157 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: Probing 169.254.241.10 Mar 10 14:55:48.359486 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: probing -> waiting-announce Mar 10 14:55:50.608901 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: Announcing 169.254.241.10 Mar 10 14:55:50.608921 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: waiting-announce -> announcing Mar 10 14:55:52.859143 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: Announcing 169.254.241.10 Mar 10 14:55:55.109042 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: announcing -> running Mar 10 14:56:18.263014 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: running -> init Mar 10 14:56:18.263017 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: STOPPED Mar 10 14:56:18.263021 jammy-2 systemd-networkd[3102]: ens8: Removing address 169.254.241.10, as the ACD client is stopped. Mar 10 14:56:18.264252 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: init -> started Mar 10 14:56:18.266537 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: started -> waiting-probe Mar 10 14:56:18.281802 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: waiting-probe -> init Mar 10 14:56:18.286309 jammy-2 systemd-networkd[3102]: ens8: Configuring IPv4ACD for address 169.254.241.10 Mar 10 14:56:18.286387 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: init -> started Mar 10 14:56:18.286404 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: started -> waiting-probe Mar 10 14:56:18.289880 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: waiting-probe -> init Mar 10 14:56:18.289883 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: STOPPED Mar 10 14:56:18.290180 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: init -> started Mar 10 14:56:18.292430 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: started -> waiting-probe Mar 10 14:56:19.360435 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: Probing 169.254.241.10 Mar 10 14:56:19.360464 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: waiting-probe -> probing Mar 10 14:56:20.859302 jammy-2 systemd-networkd[3102]: ens8: IPv4ACD: Probing 169.254.241.10