dhcpd.conf

default-lease-time 86400;                # 1 day
max-lease-time 86400;                    # 1 day
option domain-name "example2.com";
option routers 192.168.0.1;
option domain-name-servers 192.168.0.101, 192.168.0.102;
authoritative;                          # We are the "REAL" DHCP server
ddns-update-style none;
use-host-decl-names on;                 # names provided will be sent as hostname to client
option classless-routes code 121 = array of unsigned integer 8;
option classless-routes-win code 249 = array of unsigned integer 8;

#failover block (primary)
failover peer dhcp-failover {
  primary;
  address 192.168.0.101;
  port 647;
  peer address 192.168.0.102;
  peer port 647;
  max-response-delay 60;
  max-unacked-updates 10;
  load balance max seconds 3;
  mclt 3600;
  split 128;
}


shared-network NET1 {
  allow bootp;
  subnet 192.168.0.0 netmask 255.255.255.0 {
      option subnet-mask 255.255.255.0;
      option broadcast-address 192.168.0.255;
      option routers 192.168.0.1;
      option ntp-servers 192.168.0.101, 192.168.0.102;
      option domain-name-servers 192.168.0.101, 192.168.0.102;

    pool {
      failover peer "dhcp-failover";
      range 192.168.0.150 192.168.0.254;
    }

    # Network Hardware
    group {
      host  host1      { hardware ethernet 00:00:00:00:00:00; fixed-address 192.168.0.21;  }
      ...
    }
}

shared-network NET2 {
...
}

shared-network NET3 {
...
}

shared-network NET4 {
...
}

...