Linux Systemd-Networkd – Configuration Issues and Route Addition Solutions

With systemd 241 on Debian 10, I am attempting to configure systemd-networkd style networking for an edge server.

The problem I have is that when systemd-networkd starts up, it does not add the v4 or v6 routes but reports that it still is in the "configuring" state:

IDX LINK             TYPE               OPERATIONAL SETUP
  1 lo               loopback           carrier     unmanaged
  2 eth0             ether              carrier     configuring
  3 eth1             ether              carrier     configuring
  6 docker0          bridge             routable    unmanaged
  8 veth9a70b3d      ether              degraded    unmanaged
 32 ext              bond               routable    configuring
 33 int              vlan               routable    configured

Here are debug logs from networkd startup:

Aug 23 17:15:52 te1a systemd[1]: Started Network Service.
Aug 23 17:15:52 te1a systemd-networkd[29413]: ext: Created
Aug 23 17:15:52 te1a systemd-networkd[29413]: ext: Link state is up-to-date
Aug 23 17:15:52 te1a systemd-networkd[29413]: No virtualization found in DMI
Aug 23 17:15:52 te1a systemd-networkd[29413]: No virtualization found in CPUID
Aug 23 17:15:52 te1a systemd-networkd[29413]: Virtualization XEN not found, /proc/xen does not exist
Aug 23 17:15:52 te1a systemd-networkd[29413]: This platform does not support /proc/device-tree
Aug 23 17:15:53 te1a systemd-networkd[29413]: UML virtualization not found in /proc/cpuinfo.
Aug 23 17:15:53 te1a systemd-networkd[29413]: This platform does not support /proc/sysinfo
Aug 23 17:15:53 te1a systemd-networkd[29413]: Found VM virtualization none
Aug 23 17:15:53 te1a systemd-networkd[29413]: ext: found matching network '/etc/systemd/network/ext.network'
Aug 23 17:15:53 te1a systemd-networkd[29413]: ext: Setting address genmode for link
Aug 23 17:15:53 te1a systemd-networkd[29413]: ext: Enslaving by 'int'
Aug 23 17:15:53 te1a systemd-networkd[29413]: int: Creating
Aug 23 17:15:53 te1a systemd-networkd[29413]: veth9a70b3d: Link state is up-to-date
Aug 23 17:15:53 te1a systemd-networkd[29413]: veth9a70b3d: found matching network '/etc/systemd/network/veth.network
'
Aug 23 17:15:53 te1a systemd-networkd[29413]: veth9a70b3d: Unmanaged
Aug 23 17:15:53 te1a systemd-networkd[29413]: docker0: Link state is up-to-date
Aug 23 17:15:53 te1a systemd-networkd[29413]: docker0: Unmanaged
Aug 23 17:15:53 te1a systemd-networkd[29413]: eth1: Link state is up-to-date
Aug 23 17:15:53 te1a systemd-networkd[29413]: eth1: found matching network '/etc/systemd/network/eth1.network'
Aug 23 17:15:53 te1a systemd-networkd[29413]: eth1: Setting address genmode for link
Aug 23 17:15:53 te1a systemd-networkd[29413]: eth1: Enslaving by 'ext'
Aug 23 17:15:53 te1a systemd-networkd[29413]: ext: Enslaving link 'eth1'
Aug 23 17:15:53 te1a systemd-networkd[29413]: eth0: Link state is up-to-date
Aug 23 17:15:53 te1a systemd-networkd[29413]: eth0: found matching network '/etc/systemd/network/eth0.network'
Aug 23 17:15:53 te1a systemd-networkd[29413]: eth0: Setting address genmode for link
Aug 23 17:15:53 te1a systemd-networkd[29413]: eth0: Enslaving by 'ext'
Aug 23 17:15:53 te1a systemd-networkd[29413]: ext: Enslaving link 'eth0'
Aug 23 17:15:53 te1a systemd-networkd[29413]: lo: Link state is up-to-date
Aug 23 17:15:53 te1a systemd-networkd[29413]: lo: Unmanaged
Aug 23 17:15:53 te1a systemd-networkd[29413]: int: New device has no master, continuing without
Aug 23 17:15:53 te1a systemd-networkd[29413]: int: Flags change: +MULTICAST +BROADCAST
Aug 23 17:15:53 te1a systemd-networkd[29413]: int: Link 33 added
Aug 23 17:15:53 te1a systemd-networkd[29413]: int: udev initialized link
Aug 23 17:15:53 te1a systemd-networkd[29413]: int: netdev has index 33
Aug 23 17:15:53 te1a systemd-networkd[29413]: int: netdev ready
Aug 23 17:15:53 te1a systemd-networkd[29413]: int: Saved original MTU: 1500
Aug 23 17:15:53 te1a systemd-networkd[29413]: ext: Joined netdev
Aug 23 17:15:53 te1a systemd-networkd[29413]: ext: Bringing link up
Aug 23 17:15:53 te1a systemd-networkd[29413]: eth1: MAC address: 02:f9:36:9d:17:aa
Aug 23 17:15:53 te1a systemd-networkd[29413]: eth1: Flags change: +SLAVE +UP
Aug 23 17:15:53 te1a systemd-networkd[29413]: LLDP: Started LLDP client
Aug 23 17:15:53 te1a systemd-networkd[29413]: eth1: Started LLDP.
Aug 23 17:15:53 te1a systemd-networkd[29413]: eth1: Joined netdev
Aug 23 17:15:53 te1a systemd-networkd[29413]: eth0: MAC address: 02:f9:36:9d:17:aa
Aug 23 17:15:53 te1a systemd-networkd[29413]: eth0: Flags change: +SLAVE +UP
Aug 23 17:15:53 te1a systemd-networkd[29413]: LLDP: Started LLDP client
Aug 23 17:15:53 te1a systemd-networkd[29413]: eth0: Started LLDP.
Aug 23 17:15:53 te1a systemd-networkd[29413]: eth0: Joined netdev
Aug 23 17:15:53 te1a systemd-networkd[29413]: eth1: Flags change: +LOWER_UP +RUNNING
Aug 23 17:15:53 te1a systemd-networkd[29413]: eth1: Gained carrier
Aug 23 17:15:53 te1a systemd-networkd[29413]: int: Link state is up-to-date
Aug 23 17:15:53 te1a systemd-networkd[29413]: int: found matching network '/etc/systemd/network/int.network'
Aug 23 17:15:53 te1a systemd-networkd[29413]: int: Setting address genmode for link
Aug 23 17:15:53 te1a systemd-networkd[29413]: int: Bringing link up
Aug 23 17:15:53 te1a systemd-networkd[29413]: ext: Flags change: +UP
Aug 23 17:15:53 te1a systemd-networkd[29413]: LLDP: Started LLDP client
Aug 23 17:15:53 te1a systemd-networkd[29413]: ext: Started LLDP.
Aug 23 17:15:53 te1a systemd-networkd[29413]: int: Flags change: +UP +LOWER_UP
Aug 23 17:15:53 te1a systemd-networkd[29413]: LLDP: Started LLDP client
Aug 23 17:15:53 te1a systemd-networkd[29413]: int: Started LLDP.
Aug 23 17:15:53 te1a systemd-networkd[29413]: int: Flags change: +RUNNING
Aug 23 17:15:53 te1a systemd-networkd[29413]: int: Gained carrier
Aug 23 17:15:53 te1a systemd-networkd[29413]: int: Setting addresses
Aug 23 17:15:53 te1a systemd-networkd[29413]: ext: Flags change: +LOWER_UP +RUNNING
Aug 23 17:15:53 te1a systemd-networkd[29413]: ext: Gained carrier
Aug 23 17:15:53 te1a systemd-networkd[29413]: ext: Setting addresses
Aug 23 17:15:53 te1a systemd-networkd[29413]: int: Updating address: 10.0.1.210/24 (valid forever)
Aug 23 17:15:53 te1a systemd-networkd[29413]: int: Updating address: 2001:db8:2:100::d2/64 (valid forever)
Aug 23 17:15:53 te1a systemd-networkd[29413]: int: Addresses set
Aug 23 17:15:53 te1a systemd-networkd[29413]: ext: Updating address: 192.0.2.196/27 (valid forever)
Aug 23 17:15:53 te1a systemd-networkd[29413]: ext: Updating address: 2001:db8:0:ff01::c4/64 (valid forever)
Aug 23 17:15:53 te1a systemd-networkd[29413]: ext: Updating address: 192.0.2.217/32 (valid forever)
Aug 23 17:15:53 te1a systemd-networkd[29413]: ext: Updating address: 2001:db8:0:ff01::d9/128 (valid forever)
Aug 23 17:15:53 te1a systemd-networkd[29413]: ext: Addresses set
Aug 23 17:15:54 te1a systemd-networkd[29413]: eth0: Flags change: +LOWER_UP +RUNNING
Aug 23 17:15:54 te1a systemd-networkd[29413]: eth0: Gained carrier
Aug 23 17:15:55 te1a systemd-networkd[29413]: ext: Adding address: fe80::f9:36ff:fe9d:17aa/64 (valid forever)
Aug 23 17:15:55 te1a systemd-networkd[29413]: ext: Gained IPv6LL
Aug 23 17:15:55 te1a systemd-networkd[29413]: int: Adding address: fe80::f9:36ff:fe9d:17aa/64 (valid forever)
Aug 23 17:15:55 te1a systemd-networkd[29413]: int: Gained IPv6LL
Aug 23 17:15:55 te1a systemd-networkd[29413]: ext: Updating address: 2001:db8:0:ff01::d9/128 (valid forever)
Aug 23 17:15:55 te1a systemd-networkd[29413]: int: Updating address: 2001:db8:0:100::d2/64 (valid forever)
Aug 23 17:15:55 te1a systemd-networkd[29413]: int: Configured
Aug 23 17:15:55 te1a systemd-networkd[29413]: ext: Updating address: 2001:db8:0:ff01::c4/64 (valid forever)
Aug 23 17:15:56 te1a systemd-networkd[29413]: LLDP: Invoking callback for 'added' event.
Aug 23 17:15:56 te1a systemd-networkd[29413]: LLDP: Successfully processed LLDP datagram.
(repeats)

And here are the configuration files:

# eth0.network
[Match]
Name=eth0

[Link]
RequiredForOnline=no

[Network]
Bond=ext

# eth1.network
[Match]
Name=eth1

[Link]
RequiredForOnline=no

[Network]
Bond=ext

# ext.netdev
[NetDev]
Name=ext
Kind=bond

[Bond]
Mode=802.3ad
MIIMonitorSec=0.1
LACPTransmitRate=fast

# ext.network
[Match]
Name=ext

[Link]

[Network]
IPv6AcceptRA=false

[Address]
Address=192.0.2.196/27
[Route]
Gateway=192.0.2.193

[Address]
Address=2001:DB8:0:FF01::C4/64
[Route]
Gateway=2001:DB8:0:FF01::1
Metric=128

# ext.network.d/ext-a1.conf
[Match]
Name=ext

[Address]
Address=192.0.2.217/32
PreferredLifetime=0

# ext.network.d/ext-a2.conf
[Match]
Name=ext

[Address]
Address=2001:DB8:0:FF01::D9/128
PreferredLifetime=0

# ext.network.d/has-vlan-int.conf
[Match]
Name=ext

[Network]
VLAN=int

# int.netdev
[NetDev]
Name=int
Kind=vlan

[VLAN]
Id=13

# int.network
[Match]
Name=int

[Link]

[Network]
IPv6AcceptRA=false

[Address]
Address=10.0.1.210/24

[Address]
Address=2001:DB8:0:100::D2/64

# veth.network
[Match]
Name=veth*

[Link]
Unmanaged=yes
RequiredForOnline=no

What's going wrong?