Add a VLAN interface to Raspberry Pi

Step 1: Go into the interface directory

cd /etc/network/interfaces.d

Step 2: Create a new interface

sudo nano eth0.10

Step 3: Add the interface:

auto eth0.10
iface eth0.10 inet dhcp
    up ip route add 192.168.10.0/24 via 192.168.1.1

Step 4: Restart the networking

sudo systemctl restart networking

Check if the interface is up:

ip addr show eth0.50