kea-dhcp4-server orders after network-online.target, which under networkd
only waits for the WAN carrier: the vlan-* links are RequiredForOnline=no.
On stellio Kea started before networkd had addressed vlan-lan/vlan-mgmt,
failed both binds and, per its default, kept running with no socket at
all (ss -ulnp showed nothing on :67). Wireless and wired clients'
DISCOVERs reached vlan-lan and were never answered.
Set service-sockets-require-all with a bounded retry so Kea keeps trying
while networkd catches up, and Restart=on-failure on the unit for the
case it still gives up.
Verified with checks.x86_64-linux.router.
With the AP-typed match, the station-mode netdev is unmanaged until
hostapd flips it, so any wpa_supplicant/iwd/NetworkManager in the
importing config would grab the radio first and keep resetting it to
managed mode under hostapd. Fail at eval instead of at runtime.
networkd enslaves the radio to br0 once, at link init. On real hardware
(GL-MT6000, mt798x-wmac) that happens while the netdev is still in station
mode, so the kernel rejects the bridge join (IFF_DONT_BRIDGE), the link is
parked in networkd's failed state and never retried: link_reconfigure_impl()
is a no-op while the matching .network file is unchanged, and the udev
'iw set type __ap' hook meant to pre-empt this loses the race. Wireless
clients associate but their DHCP never reaches vlan-lan.
Match on WLANInterfaceType=ap as well as the name. The station-mode netdev
then matches nothing (unmanaged) and the file first matches when hostapd
has switched the radio to AP and raised carrier, so the enslave succeeds
on the first try. Drop the udev hook.
Verified with checks.x86_64-linux.router (hwsim STA lease over the bridge).
kurogeek