IN the past dhcpd scopes were the only way togo, but for a while now DHCPD offers a type of clustering of DHCP servers. The setup is not to hard. Full detail here, but I have cut and paste the details here to make things simpler.
Server examples:
dhcp-server-a (192.168.200.2/24)
authoritative;
ddns-update-style none;
failover peer "dhcp-failover" {
primary; # declare this to be the primary server
address 192.168.200.2;
port 647;
peer address 192.168.200.3;
peer port 647;
max-response-delay 30;
max-unacked-updates 10;
load balance max seconds 3;
mclt 1800;
split 128;
}
subnet 192.168.200.0 netmask 255.255.255.0 {
option subnet-mask 255.255.255.0;
option broadcast-address 192.168.200.255;
option routers 192.168.200.1;
option domain-name-servers 192.168.200.1;
pool {
failover peer "dhcp-failover";
max-lease-time 1800; # 30 minutes
range 192.168.200.100 192.168.200.254;
}
}
dhcp-server-b (192.168.200.3/24)
#
# /etc/dhcpd.conf for secondary DHCP server
#
authoritative;
ddns-update-style none;
failover peer "dhcp-failover" {
secondary; # declare this to be the secondary server
address 192.168.200.3;
port 647;
peer address 192.168.200.2;
peer port 647;
max-response-delay 30;
max-unacked-updates 10;
load balance max seconds 3;
}
subnet 192.168.200.0 netmask 255.255.255.0 {
option subnet-mask 255.255.255.0;
option broadcast-address 192.168.200.255;
option routers 192.168.200.1;
option domain-name-servers 192.168.200.1;
pool {
failover peer "dhcp-failover";
max-lease-time 1800; # 30 minutes
range 192.168.200.100 192.168.200.254;
}
}