Preface and issue
I have an Ubuntu 21.10 (Impish) server, which network is managed by netplan and systemd-networkd.
My /etc/netplan/01-netcfg.yaml looks like this:
network:
version: 2
renderer: networkd
ethernets:
eth0:
addresses:
- 1.2.3.4/32
- dead:beef:f00:ba1::2/64
routes:
- on-link: true
to: 0.0.0.0/0
via: 1.2.1.2
- on-link: true
to: default
via: fe80::1
vlans:
eth0.1234:
id: 1234
link: eth0
mtu: 1400
addresses:
- 10.0.0.2/25
routes:
- on-link: true
to: 10.0.0.128/24
via: 10.0.0.1
ip a reports the correct IPs for the three interfaces (lo, eth0, eth0.1234@eth0). Ping and other network traffic works (in-/outbound, outside/vlan).
However, when I reboot the server, sshd.service fails to start at boot time with the following error:
Dec 14 19:18:02 srvnme sshd[1380]: error: Bind to port 22 on dead:beef:f00:ba1::2 failed: Cannot assign requested address.
Dec 14 19:18:02 srvnme sshd[1380]: error: Bind to port 22 on 1.2.3.4 failed: Cannot assign requested address.
Dec 14 19:18:02 srvnme sshd[1380]: fatal: Cannot bind any address.
While boot, the server does not show any issues related to the interface
Dec 14 19:18:02 srvnme kernel: [ 1.240607] r8169 0000:22:00.0 eth0: RTL8168h/8111h, de:ad:be:ef:f0:00, XID 541, IRQ 154
Dec 14 19:18:02 srvnme kernel: [ 1.240738] r8169 0000:22:00.0 eth0: jumbo features [frames: 9194 bytes, tx checksumming: ko]
Dec 14 19:18:02 srvnme kernel: [ 5.046402] r8169 0000:22:00.0 eth0: Link is Down
Dec 14 19:18:03 srvnme kernel: [ 8.054249] r8169 0000:22:00.0 eth0: Link is Up - 1Gbps/Full - flow control rx/tx
Dec 14 19:18:03 srvnme kernel: [ 8.054273] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
As stated, after a server reboot, I have to hook up a KVM to the server to restart the OpenSSH server to be able to ssh into the server again.
Non-working solutions (so far)
I edited the OpenSSH server configuration (systemctl edit sshd) and tried two approaces:
[Unit]
Requires=systemd-networkd.service
After=systemd-networkd.service
BindsTo=systemd-networkd.service
[Unit]
Wants=network-online.target
After=network-online.target
Both approaches had no effect.
How to fix the OpenSSH does not start at server boot issue?
