port number - designation - port2vlan - port setting pvid
1 - WAN1 input - 2 excl, 3 excl, 4 untagged - 4
2 - WAN2 input - 2 excl, 3 untagged, 4 excl - 3
3-12 servers - 2 tagged, 3 tagged, 4 tagged - 2
13 - WAN1 to router - 2 excl, 3 excl, 4 untagged - 4
14 - WAN2 to router - 2 excl, 3 untagged, 4 excl - 3
15-24 servers - 2 tagged, 3 tagged, 4 tagged - 2
G1 - LAN from router - 2 untagged, 3 excl, 4 excl - 2
G2-G4 servers - 2 tagged, 3 tagged, 4 tagged - 2

# LAN
auto enp1s0.2
iface enp1s0.2 inet static
        address 10.1.4.10
        gateway 10.1.0.1
        netmask 255.255.252.0
        dns-nameservers 10.1.0.1
        vlan-raw-device enp1s0
        mtu 1500

# Netia
allow-hotplug enp1s0.3
iface enp1s0.3 inet static
        address 192.168.0.72
        gateway 192.168.0.65
        netmask 255.255.255.240
        dns-nameservers 8.8.8.8 8.8.4.4
        vlan-raw-device enp1s0
        mtu 1500

# Connected
allow-hotplug enp1s0.4
iface enp1s0.4 inet static
        address 192.168.1.168
        gateway 192.168.1.161
        netmask 255.255.255.240
        dns-nameservers 8.8.8.8 8.8.4.4
        vlan-raw-device enp1s0
        mtu 1500

Set name-type for VLAN subsystem. Should be visible in /proc/net/vlan/config
RTNETLINK answers: File exists
ifup: failed to bring up enp1s0.3

ifdown: interface enp1s0.3 not configured