DHCP

Check DHCP leases

/var/lib/dhcp/dhclient.leases

Force DNS

For one interface

nano /etc/dhcp/dhclient.conf

interface "eth0" {
   prepend domain-name-servers 127.0.0.1;
}

For all interfaces

prepend domain-name-servers 127.0.0.1;

DHCP Server

sudo apt-get update
sudo apt search isc-dhcp
sudo apt install isc-dhcp-server
sudo cp /etc/dhcp/dhcpd.conf{,.backup}
sudo nano /etc/dhcp/dhcpd.conf

option domain-name "rra.lan";
option domain-name-servers 10.0.232.30, 8.8.8.8;

default-lease-time 60000000;
max-lease-time 720000000000;

ddns-update-style none;

authoritative;

log-facility local7;


subnet 192.168.0.0 netmask 255.255.255.0 {
    range 192.168.0.1 192.168.0.200;
    option subnet-mask 255.255.255.0;
    option broadcast-address 192.168.0.255;
}

host dhcpi {
   hardware ethernet B8:27:EB:4D:E4:37;
   fixed-address 192.168.0.254;
}

host muyfalso {
   hardware ethernet FF:FF:FF:FF:FF:FF;
   fixed-address 192.168.0.1;
}

sudo nano /etc/default/isc-dhcp-server

INTERFACESv4="eth0"

systemctl restart isc-dhcp-server
systemctl status isc-dhcp-server