StaticIPAddresses

Edit /etc/dhcpcd.conf as follows:-

       interface eth0
       static ip_address=10.1.1.30/24
       static routers=10.1.1.1
       static domain_name_servers=10.1.1.1

       interface wlan0
       static ip_address=10.1.1.31/24
       static routers=10.1.1.1
       static domain_name_servers=10.1.1.1