sudo su
cd /etc/netplan/
ls -al
ifconfig
nano /etc/netplan/........

network:
    version: 2
    ethernets:
       eth0:
          dhcp4: yes
          addresses: [192.168.1.12/24]
          gateway4: 192.168.1.1
          nameservers:
            addresses: [8.8.8.8,8.8.4.4]

	eth1:
          dhcp4: no
          addresses: [10.0.0.10/24]
          addresses: [10.0.0.20/24]
          addresses: [10.0.0.30/24]
          nameservers:
            addresses: [8.8.8.8,8.8.4.4]
CTRL+X

.....

ifconfig

apt update
apt install isc-dhcp-server

nano /etc/dhcp/dhcpd.conf

---------
default-lease-time 600;
max-lease-time 7200;

ddns-update-style none;

option domain-name-servers 8.8.8.8, 8.8.4.4;
option routers 192.168.1.1;

subnet 192.168.1.0 netmask 255.255.255.0 {
range 192.168.1.10 192.168.1.100;
option broadcast-address 192.168.1.255;
}
---------
CTRL+X

restart serwera dhcp: service isc-dhcp-server restart