pfSense

Hi Jim P,
please recheck this and do not reject it that fast. it just luck that sometimes the service report normal state, but they do not exchange lease information correctly, cause oft the ports.
we got version 2.2.4. if you read the generated configuration files, you will see the error with the peer and local port.
we reproduced this issue on multiple clusters.

I did, and it works fine. You have a problem in your configuration if the DHCP configuration files are not correct as you have shown. Please discuss it in the forum before opening a ticket.

Ok, if you whish i will discuss the issue in the forum. But as you know the webui, there is no option to configure the ports and so the generated config is logicaly wrong and missing some needed options.(see also: https://kb.isc.org/article/AA-00502/0/A-Basic-Guide-to-Configuring-DHCP-Failover.html)

Please leave the discussion for the forum.

When configured properly, it has a proper configuration:

Primary:

$ cat /var/dhcpd/etc/dhcpd.conf

option domain-name "dw.example.com";
option ldap-server code 95 = text;
option domain-search-list code 119 = text;
option arch code 93 = unsigned integer 16; # RFC4578

default-lease-time 7200;
max-lease-time 86400;
log-facility local7;
one-lease-per-client true;
deny duplicates;
ping-check true;
update-conflict-detection false;
authoritative;
failover peer "dhcp_lan" {
  primary;
  address 10.11.0.2;
  port 519;
  peer address 10.11.0.3;
  peer port 520;
  max-response-delay 10;
  max-unacked-updates 10;
  split 128;
  mclt 600;

  load balance max seconds 3;
}

subnet 10.11.0.0 netmask 255.255.255.0 {
    pool {
        option domain-name-servers 10.11.0.1;
        deny dynamic bootp clients;
        failover peer "dhcp_lan";
        range 10.11.0.11 10.11.0.245;
    }

    option routers 10.11.0.1;
    option domain-name-servers 10.11.0.1;

}

Secondary:

$ cat /var/dhcpd/etc/dhcpd.conf

option domain-name "dw.example.com";
option ldap-server code 95 = text;
option domain-search-list code 119 = text;
option arch code 93 = unsigned integer 16; # RFC4578

default-lease-time 7200;
max-lease-time 86400;
log-facility local7;
one-lease-per-client true;
deny duplicates;
ping-check true;
update-conflict-detection false;
authoritative;
failover peer "dhcp_lan" {
  secondary;
  address 10.11.0.3;
  port 520;
  peer address 10.11.0.2;
  peer port 519;
  max-response-delay 10;
  max-unacked-updates 10;

  load balance max seconds 3;
}

subnet 10.11.0.0 netmask 255.255.255.0 {
    pool {
        option domain-name-servers 10.11.0.1;
        deny dynamic bootp clients;
        failover peer "dhcp_lan";
        range 10.11.0.11 10.11.0.245;
    }

    option routers 10.11.0.1;
    option domain-name-servers 10.11.0.1;

}

Primary:

Secondary:

If yours does not match the above, you have a configuration problem, which can be discussed on the forum.