option domain-name-servers <%= ', '.join(@dns_resolvers_ipv4) %>;
option ntp-servers <%= ', '.join(@ntp_servers_ipv4) %>;

# specify API server URL (RFC8910)
option default-url "https://<%= @service_name %>/api/captive-portal";

default-lease-time 600;
max-lease-time 3600;

authoritative;

<% if @instances.length == 2 -%>
failover peer "dhcp-peer" {
    <% if @instance_index == 0 %>primary<% else %>secondary<% end %>;
    address <%= @instances[@instance_index]['external_ipv4'] %>;
    peer address <%= @instances[1-@instance_index]['external_ipv4'] %>;
    max-response-delay 60;
    max-unacked-updates 10;
    load balance max seconds 3;
<% if @instance_index == 0 -%>
    split 128;
    mclt 180;
<%- end %>
}
<%- end %>

subnet <%= @client_ipv4_net %> netmask <%= @client_netmask %> {
    option routers <%= @client_ipv4_gateway %>;
    pool {
        range <%= @client_ipv4_dhcp_from %> <%= @client_ipv4_dhcp_to %>;
<% if @instances.length == 2 -%>
        failover peer "dhcp-peer";
<%- end %>
    }
}