Upstream bug: https://gitlab.isc.org/isc-projects/kea/-/issues/3162
Based on config in https://vyos.dev/T7822
set interfaces ethernet eth1 address 192.0.2.1/30 set interfaces ethernet eth1 address 100.64.0.1/24 set interfaces ethernet eth1 description LAN set interfaces ethernet eth1 vrf red set vrf bind-to-all set vrf name red service dhcp-server listen-interface eth1 set vrf name red service dhcp-server shared-network-name LANv4 authoritative set vrf name red service dhcp-server shared-network-name LANv4 subnet 100.64.0.0/24 range R1 start 100.64.0.10 set vrf name red service dhcp-server shared-network-name LANv4 subnet 100.64.0.0/24 range R1 stop 100.64.0.254 set vrf name red service dhcp-server shared-network-name LANv4 subnet 100.64.0.0/24 subnet-id 1 set vrf name red table 1010
No IPs from 100.64.0.0/24 subnet will be handed out.
Kea log:
2025-09-20 18:33:56.551 DEBUG [kea-dhcp4.packets/3444.140013113463872] DHCP4_BUFFER_RECEIVED received buffer from 0.0.0.0:68 to 255.255.255.255:67 over interface eth1 2025-09-20 18:33:56.551 DEBUG [kea-dhcp4.options/3444.140013062235840] DHCP4_BUFFER_UNPACK parsing buffer received from 0.0.0.0 to 255.255.255.255 over interface eth1 2025-09-20 18:33:56.551 INFO [kea-dhcp4.dhcp4/3444.140013062235840] DHCP4_QUERY_LABEL received query: [hwtype=1 bc:24:11:7a:94:08], cid=[no info], tid=0x8d4ac112 2025-09-20 18:33:56.551 DEBUG [kea-dhcp4.dhcpsrv/3444.140013062235840] DHCPSRV_SUBNET4_SELECT_NO_RAI_OPTIONS No RAI options found to use for subnet selection. 2025-09-20 18:33:56.551 DEBUG [kea-dhcp4.dhcpsrv/3444.140013062235840] DHCPSRV_SUBNET4_SELECT_NO_RELAY_ADDRESS Relay address (giaddr) in client packet is empty. 2025-09-20 18:33:56.551 DEBUG [kea-dhcp4.dhcpsrv/3444.140013062235840] DHCPSRV_SUBNET4_SELECT_BY_INTERFACE_NO_MATCH No subnet matches interface: eth1 2025-09-20 18:33:56.551 DEBUG [kea-dhcp4.dhcpsrv/3444.140013062235840] DHCPSRV_SUBNET4_SELECT_BY_ADDRESS_NO_MATCH No subnet matches address: 192.0.2.1 2025-09-20 18:33:56.551 DEBUG [kea-dhcp4.packets/3444.140013062235840] DHCP4_SUBNET_SELECTION_FAILED [hwtype=1 bc:24:11:7a:94:08], cid=[no info], tid=0x8d4ac112: failed to select subnet for the client 2025-09-20 18:33:56.551 DEBUG [kea-dhcp4.bad-packets/3444.140013062235840] DHCP4_PACKET_DROP_0002 [hwtype=1 bc:24:11:7a:94:08], cid=[no info], tid=0x8d4ac112, from interface eth1: no suitable subnet configured for a direct client