problem with failover server selection

Ana Gallardo Gómez anaougu at gmail.com
Wed Mar 16 09:09:44 UTC 2011


Hello,

I'm using ISC DHCP Server 4.1.1-P1 with debian squezze.

I have two ISC DHCP Server running with failover. My problem is that
sometimes both servers respond to DHCPDISCOVER.

My configuration
------------------------

--- PRIMARY SERVER

# cat /etc/dhcp/dhcpd.conf
include "/etc/dhcp/dhcpd.conf.primary";
include "/etc/dhcp/dhcpd.conf.subnetprimary";

# cat /etc/dhcp/dhcpd.conf.primary
failover peer "failover-open" {
  primary;
  address 10.253.40.2;
  port 647;
  peer address 10.253.40.1;
  peer port 647;
  max-response-delay 60;
  max-unacked-updates 10;
  mclt 3600;
  split 128;
  load balance max seconds 3;
}

failover peer "failover-8021X" {
  primary;
  address 10.254.40.2;
  port 647;
  peer address 10.254.40.1;
  peer port 647;
  max-response-delay 60;
  max-unacked-updates 10;
  mclt 3600;
  split 128;
  load balance max seconds 3;

}

# cat /etc/dhcp/dhcpd.conf.subnetprimary
option domain-name "xxx.es";
option domain-name-servers a.b.c.d;
default-lease-time 7200;
max-lease-time 7200;
ddns-update-style none;
authoritative;
deny duplicates;
deny declines;
one-lease-per-client on;

subnet a.b.f.0 netmask 255.255.255.0 {
}

subnet 10.253.40.0 netmask 255.255.252.0 {
  option broadcast-address 10.253.43.255;
  pool {
    failover peer "failover-open";
    range 10.253.40.5 10.253.43.254;
    option routers 10.253.40.2;
  }
}

subnet 10.254.40.0 netmask 255.255.255.0 {
  option broadcast-address 10.254.40.255;
  pool {
    failover peer "failover-80211X";
    range 10.254.40.5 10.254.40.254;
    option routers 10.254.40.2;
  }
}


--- SECONDARY SERVER

# cat /etc/dhcp/dhcpd.conf
include "/etc/dhcp/dhcpd.conf.secondary";
include "/etc/dhcp/dhcpd.conf.subnetsecondary";

# cat /etc/dhcp/dhcpd.conf.secondary
failover peer "failover-open" {
  secondary;
  address 10.253.40.1;
  port 647;
  peer address 10.253.40.2;
  peer port 647;
  max-response-delay 60;
  max-unacked-updates 10;
  split 128;
  load balance max seconds 3;
}

failover peer "failover-8021X" {
  secondary;
  address 10.254.40.1;
  port 647;
  peer address 10.254.40.2;
  peer port 647;
  max-response-delay 60;
  max-unacked-updates 10;
  split 128;
  load balance max seconds 3;

}

# cat /etc/dhcp/dhcpd.conf.subnetsecondary
option domain-name "xxx.es";
option domain-name-servers a.b.c.d;
default-lease-time 7200;
max-lease-time 7200;
ddns-update-style none;
authoritative;
deny duplicates;
deny declines;
one-lease-per-client on;

subnet a.b.g.0 netmask 255.255.255.0 {
}

subnet 10.253.40.0 netmask 255.255.252.0 {
  option broadcast-address 10.253.43.255;
  pool {
    failover peer "failover-open";
    range 10.253.40.5 10.253.43.254;
    option routers 10.253.40.1;
  }
}

subnet 10.254.40.0 netmask 255.255.255.0 {
  option broadcast-address 10.254.40.255;
  pool {
    failover peer "failover-80211X";
    range 10.254.40.5 10.254.40.254;
    option routers 10.254.40.1;
  }
}

LOG PRIMARY:

Mar 15 10:05:12 dhcpd: DHCPDISCOVER from 01:11:5d:21:48:b4 via vlan1223
Mar 15 10:05:13  dhcpd: DHCPOFFER on 10.253.40.64 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 10:05:16  dhcpd: DHCPACK to 10.253.40.64 (01:11:5d:21:48:b4) via
vlan1223
Mar 15 10:06:20  dhcpd: DHCPACK to 10.253.40.64 (01:11:5d:21:48:b4) via
vlan1223
Mar 15 10:07:23  dhcpd: DHCPACK to 10.253.40.64 (01:11:5d:21:48:b4) via
vlan1223

Mar 15 12:30:43  dhcpd: DHCPDISCOVER from 01:11:5d:21:48:b4 via vlan1223
Mar 15 12:30:44  dhcpd: DHCPOFFER on 10.253.40.102 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 12:30:44  dhcpd: uid lease 10.253.40.102 for client 01:11:5d:21:48:b4
is duplicate on 10.253.40.0/22
Mar 15 12:30:44  dhcpd: DHCPREQUEST for 10.253.40.45 (10.253.40.1) from
01:11:5d:21:48:b4 (Tania-PC) via vlan1223: lease owned by peer
Mar 15 12:30:47  dhcpd: DHCPACK to 10.253.40.45 (01:11:5d:21:48:b4) via
vlan1223
Mar 15 12:59:25  dhcpd: DHCPREQUEST for 10.253.40.45 from 01:11:5d:21:48:b4
(Tania-PC) via vlan1223
Mar 15 12:59:25  dhcpd: DHCPACK on 10.253.40.45 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 12:59:26  dhcpd: DHCPACK to 10.253.40.45 (01:11:5d:21:48:b4) via
vlan1223
Mar 15 13:38:55  dhcpd: DHCPREQUEST for 10.253.40.45 from 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:38:55  dhcpd: DHCPACK on 10.253.40.45 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:39:08  dhcpd: DHCPREQUEST for 10.253.40.45 from 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:39:08  dhcpd: DHCPACK on 10.253.40.45 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:39:27  dhcpd: DHCPACK to 10.253.40.45 (01:11:5d:21:48:b4) via
vlan1223
Mar 15 13:39:29  dhcpd: DHCPACK to 10.253.40.45 (01:11:5d:21:48:b4) via
vlan1223
Mar 15 13:39:54  dhcpd: DHCPREQUEST for 10.253.40.45 from 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:39:54  dhcpd: DHCPACK on 10.253.40.45 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:40:56  dhcpd: DHCPACK to 10.253.40.45 (01:11:5d:21:48:b4) via
vlan1223
Mar 15 13:42:01  dhcpd: DHCPREQUEST for 10.253.40.45 from 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:42:01  dhcpd: DHCPACK on 10.253.40.45 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:42:11  dhcpd: DHCPACK to 10.253.40.45 (01:11:5d:21:48:b4) via
vlan1223
Mar 15 13:46:02  dhcpd: DHCPREQUEST for 10.253.40.45 from 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:46:02  dhcpd: DHCPACK on 10.253.40.45 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:46:05  dhcpd: DHCPACK to 10.253.40.45 (01:11:5d:21:48:b4) via
vlan1223
Mar 15 13:46:59  dhcpd: DHCPREQUEST for 10.253.40.45 from 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:46:59  dhcpd: DHCPACK on 10.253.40.45 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:47:01  dhcpd: DHCPACK to 10.253.40.45 (01:11:5d:21:48:b4) via
vlan1223
Mar 15 13:49:29  dhcpd: DHCPREQUEST for 10.253.40.45 from 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:49:29  dhcpd: DHCPACK on 10.253.40.45 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:53:14  dhcpd: DHCPREQUEST for 10.253.40.45 from 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:53:14  dhcpd: DHCPACK on 10.253.40.45 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:53:15  dhcpd: DHCPACK to 10.253.40.45 (01:11:5d:21:48:b4) via
vlan1223
Mar 15 13:55:07  dhcpd: DHCPREQUEST for 10.253.40.45 from 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:55:07  dhcpd: DHCPACK on 10.253.40.45 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:55:11  dhcpd: DHCPACK to 10.253.40.45 (01:11:5d:21:48:b4) via
vlan1223
Mar 15 13:56:47  dhcpd: DHCPREQUEST for 10.253.40.45 from 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:56:47  dhcpd: DHCPACK on 10.253.40.45 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:56:49  dhcpd: DHCPACK to 10.253.40.45 (01:11:5d:21:48:b4) via
vlan1223

LOG SECONDARY:

Mar 15 10:05:12  dhcpd: DHCPDISCOVER from 01:11:5d:21:48:b4 via vlan1223
Mar 15 10:05:13  dhcpd: DHCPOFFER on 10.253.40.64 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 10:05:13  dhcpd: DHCPREQUEST for 10.253.40.64 (10.253.40.1) from
01:11:5d:21:48:b4 (usuario1) via vlan1223
Mar 15 10:05:13  dhcpd: DHCPACK on 10.253.40.64 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 10:05:18  dhcpd: DHCPACK to 10.253.40.64 (01:11:5d:21:48:b4) via
vlan1223
Mar 15 10:06:21  dhcpd: DHCPACK to 10.253.40.64 (01:11:5d:21:48:b4) via
vlan1223
Mar 15 10:07:25  dhcpd: DHCPACK to 10.253.40.64 (01:11:5d:21:48:b4) via
vlan1223

Mar 15 12:30:45  dhcpd: DHCPDISCOVER from 01:11:5d:21:48:b4 via vlan1223
Mar 15 12:30:46  dhcpd: DHCPOFFER on 10.253.40.45 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 12:30:46  dhcpd: DHCPREQUEST for 10.253.40.45 (10.253.40.1) from
01:11:5d:21:48:b4 (usuario1) via vlan1223
Mar 15 12:30:46  dhcpd: DHCPACK on 10.253.40.45 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 12:30:49  dhcpd: DHCPACK to 10.253.40.45 (01:11:5d:21:48:b4) via
vlan1223
Mar 15 12:59:24  dhcpd: DHCPREQUEST for 10.253.40.45 from 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 12:59:24  dhcpd: DHCPACK on 10.253.40.45 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 12:59:28  dhcpd: DHCPACK to 10.253.40.45 (01:11:5d:21:48:b4) via
vlan1223
Mar 15 13:38:57  dhcpd: DHCPREQUEST for 10.253.40.45 from 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:38:57  dhcpd: DHCPACK on 10.253.40.45 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:39:11  dhcpd: DHCPREQUEST for 10.253.40.45 from 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:39:11  dhcpd: DHCPACK on 10.253.40.45 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:39:29  dhcpd: DHCPACK to 10.253.40.45 (01:11:5d:21:48:b4) via
vlan1223
Mar 15 13:39:32  dhcpd: DHCPACK to 10.253.40.45 (01:11:5d:21:48:b4) via
vlan1223
Mar 15 13:39:56  dhcpd: DHCPREQUEST for 10.253.40.45 from 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:39:56  dhcpd: DHCPACK on 10.253.40.45 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:40:58  dhcpd: DHCPACK to 10.253.40.45 (01:11:5d:21:48:b4) via
vlan1223
Mar 15 13:42:03  dhcpd: DHCPREQUEST for 10.253.40.45 from 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:42:03  dhcpd: DHCPACK on 10.253.40.45 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:42:13  dhcpd: DHCPACK to 10.253.40.45 (01:11:5d:21:48:b4) via
vlan1223
Mar 15 13:46:04  dhcpd: DHCPREQUEST for 10.253.40.45 from 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:46:04  dhcpd: DHCPACK on 10.253.40.45 to 01:11:5d:21:48:b4
(usuario1) via vlan1223
Mar 15 13:46:07  dhcpd: DHCPACK to 10.253.40.45 (01:11:5d:21:48:b4) via
vlan1223

I can't understand two things:

1. Why the secondary server offer two diferent IP's: 10.253.40.64 and
10.253.40.45??
2. Why primary and secondary server respond to the Mar 15 12:30:45  dhcpd:
DHCPDISCOVER??


Thank you in advance and sorry for my english.

::::::::::::::::::::::::::::::::::::
:: Ana Gallardo Gómez ::
::::::::::::::::::::::::::::::::::::
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