Offer in a dhcp fo setup with split 255

[Meike Stone]

Hello,

I've configured two dhcpd servers (dhcpd01 and dhcpd02) in a fail over
association.

The primary is connected directly in the client subnet. The secondary
is reachable via dhcp relay (ip helper) from the client subnet.
The primary should answer every time, if available. Therefor the split is 255.

But after a DISCOVER from a client in the client subnet, both server
answer immediately with a OFFER.
Is this the correct behavior in a dhcp FO setup?

Thanks for help
Meike


Here are the messages from the Logfile:


dhcpd01 (primary DHCP FO, 192.168.140.44 )
===================================
2011-10-06T10:46:51+02:00 daemon (none) dhcpd[2530]: info DHCPDISCOVER
from 00:0a:02:11:22:33 via eth1
2011-10-06T10:46:52+02:00 daemon (none) dhcpd[2530]: info DHCPOFFER on
192.168.140.223 to 00:0a:02:11:22:33 (dhcp-192-168-140-223) via eth1
relay eth1 lease-duration 120

dhcpd02 (secondary DHCP FO, 192.168.144.70)
===================================
2011-10-06T10:46:51+02:00 daemon (none) dhcpd[28725]: info
DHCPDISCOVER from 00:0a:02:11:22:33 via 192.168.140.2
2011-10-06T10:46:52+02:00 daemon (none) dhcpd[28725]: info DHCPOFFER
on 192.168.140.225 to 00:0a:02:11:22:33 (dhcp-192-168-140-225) via
eth2 relay 192.168.140.2 lease-duration 120



And here the configuration:


dhcpd01 (primary DHCP FO, 192.168.140.44 )
===================================
authoritative;
default-lease-time 86400;
min-lease-time 86400;
max-lease-time 86400;
ping-number 1;
ping-timeout 1;
log-facility daemon;


failover peer "dhcp-failover"
{
  primary;
  address 192.168.140.44;
  port 647;

  peer address 192.168.144.70;
  peer port 647;

  max-response-delay 60;
  max-unacked-updates 10;
  mclt 3600;
  split 255;
 load balance max seconds 3;
}

class "pxe-boot" {
	match if (substring ( option  vendor-class-identifier, 0, 9) =
"PXEClient") or (option  dhcp-client-identifier = "null");
	default-lease-time 60;
	min-lease-time 60;
	max-lease-time 60;
}

subnet 192.168.140.0 netmask 255.255.255.0 {
	option routers 192.168.140.1;

	pool {
		failover peer "dhcp-failover";
		deny dynamic bootp clients;
		range 192.168.140.80 192.168.140.220;
		deny members of "pxe-boot";
	}
	pool {
		failover peer "dhcp-failover";
		deny dynamic bootp clients;
		range 192.168.140.221 192.168.140.229;
		allow members of "pxe-boot";
	}
}



dhcpd02 (secondary DHCP FO, 192.168.144.70)
===================================

authoritative;
default-lease-time 86400;
min-lease-time 86400;
max-lease-time 86400;
ping-number 1;
ping-timeout 1;
log-facility daemon;


failover peer "dhcp-failover"
{
  secondary;
  address 192.168.144.70;
  port 647;

  peer address 192.168.140.44;
  peer port 647;

  max-response-delay 60;
  max-unacked-updates 10;
 load balance max seconds 3;
}



class "pxe-boot" {
	match if (substring ( option  vendor-class-identifier, 0, 9) =
"PXEClient") or (option  dhcp-client-identifier = "null");
	default-lease-time 60;
	min-lease-time 60;
	max-lease-time 60;
}

subnet 192.168.140.0 netmask 255.255.255.0 {
    option routers 192.168.140.1;

	pool {
		failover peer "dhcp-failover";
		deny dynamic bootp clients;
		range 192.168.140.80 192.168.140.220;
		deny members of "pxe-boot";
	}
	pool {
		failover peer "dhcp-failover";
		deny dynamic bootp clients;
		range 192.168.140.221 192.168.140.229;
		allow members of "pxe-boot";
	}
}