Systemd networkd not working for wired ethernet

Question

I followed Use systemd-networkd for general networking to switch to systemd-networkd on my Raspberry Pi 4. It works for Wi-Fi but not for wired. Wired worked before with raspbian default networking.

/etc/systemd/network/20-wired.network:

[Match]
Name=eth0
[Network]
DHCP=yes

/etc/systemd/network/25-wireless.network:

[Match]
Name=wlan0
[Network]
DHCP=yes

journalctl -b -u systemd-networkd with SYSTEMD_LOG_LEVEL=debug is repeating:

DHCP CLIENT (0x*******): DISCOVER
LLDP: Invoking callback for 'refreshed' event.
LLDP: Successfully processes LLDP datagram.
LLDP: Invoking callback for 'refreshed' event.
LLDP: Successfully processes LLDP datagram.
DHCP CLIENT (0x*******): DISCOVER
LLDP: Invoking callback for 'refreshed' event.
LLDP: Successfully processes LLDP datagram.
LLDP: Invoking callback for 'refreshed' event.
LLDP: Successfully processes LLDP datagram.
sudo tcpdump -n -tttt -i eth0 port 67 and port 68
2021-02-24 12:44:28.756015 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:44:31.776586 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:44:34.796568 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:44:52.267688 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from this_pi_mac, length 293
2021-02-24 12:44:54.560958 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from another_pi_mac, length 300
2021-02-24 12:44:57.868431 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:44:59.261715 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from another_pi_mac, length 300
2021-02-24 12:45:00.879388 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:45:03.890775 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:45:07.895642 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from another_pi_mac, length 300
2021-02-24 12:45:23.778606 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from another_pi_mac, length 300
2021-02-24 12:45:26.940733 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:45:29.950853 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:45:32.961207 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:45:55.906876 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from this_pi_mac, length 293
2021-02-24 12:45:56.012936 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:45:59.024158 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:46:02.033746 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:46:25.085108 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:46:28.095255 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:46:31.105314 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:46:54.157369 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:46:57.167301 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:47:00.178444 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:47:00.860402 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from this_pi_mac, length 293
2021-02-24 12:47:23.229390 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:47:26.239402 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:47:29.249791 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:47:52.311009 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:47:55.321653 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:47:58.341471 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:48:05.575106 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from this_pi_mac, length 293
2021-02-24 12:48:21.404145 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:48:24.423359 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:48:27.443604 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:48:50.515474 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:48:53.535446 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:48:56.555645 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:49:09.478749 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from this_pi_mac, length 293
2021-02-24 12:49:19.637457 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:49:22.657678 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:49:25.677909 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:49:48.749747 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:49:51.770046 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:49:54.790148 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:50:14.493308 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from this_pi_mac, length 293
2021-02-24 12:50:17.852689 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:50:20.871987 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289
2021-02-24 12:50:23.882870 IP 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from someother_pi_mac, length 289

What I see is a lot of DHCP requests, but no answers. Are you sure there is a DHCP server on the wired LAN? — Ljm Dullaart, Feb 24 '21 at 17:45

score 1 · Answer 1 · answered Feb 24 '21 at 15:28

It is giving you garbage for the netmask, I always see 255.255.255.0 for that one on my working addresses. Track down that setting origin and you will solve it.

root@buster-raspi:~# ifconfig -a
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
    inet 192.168.0.116  netmask 255.255.255.0  broadcast 192.168.0.255
    inet6 fe80::dea6:32ff:fed8:8c2c  prefixlen 64  scopeid 0x20<link>

Where do you see a netmask? – Ljm Dullaart Feb 24 '21 at 17:43 — Ljm Dullaart, Feb 24 '21 at 17:43

Systemd networkd not working for wired ethernet

1 Answers1