uid lease duplicate problem

[Sue True]

We are running 4.2.5-P1, started to get IP conflict report since migrated 
the servers to failover config couple of months ago.

We can't tell if the failover config could be one of the reasons that 
might caused the conflict, I noticed there are lots of uid lease duplicate 
logs.

I've tried both the configuration option " --enable-secs-byteorder" and 
patch provided by Wim Vandersmissen 
https://lists.isc.org/pipermail/dhcp-users/2010-April/011669.html

But none of those helps, both servers OFFER with different IPs, which also 
caused client IP constantly change, pool churn.

Has anyone run into the same problem or know how to stop the uid 
duplicate?

Here are some info about failover

     - we're using 'split 128' for the load-balancing
     - we're not using any reservations or static lease
     - we're using 'one-lease-per-client'
     - both partners are in normal state (00:00:00:02)
     - MCLT = 1800

Here are some logs:

Jun  5 05:56:02 dhcp-2 dhcpd: DHCPRELEASE of 10.10.2.143 from fc:0f:e6:c4:e8:d1 via eth0 (found)
Jun  5 08:30:44 dhcp-1 dhcpd: DHCPDISCOVER from fc:0f:e6:c4:e8:d1 via 10.10.2.252: load balance to peer dhcp
Jun  5 08:30:44 dhcp-1 dhcpd: DHCPDISCOVER from fc:0f:e6:c4:e8:d1 via 10.10.2.253: load balance to peer dhcp
Jun  5 08:30:44 dhcp-2 dhcpd: DHCPDISCOVER from fc:0f:e6:c4:e8:d1 via 10.10.2.252
Jun  5 08:30:45 dhcp-2 dhcpd: DHCPOFFER on 10.10.2.143 ends 2014/06/05:12:32:44 to fc:0f:e6:c4:e8:d1 via 10.10.2.252
Jun  5 08:30:45 dhcp-1 dhcpd: uid lease 10.10.2.161 for client fc:0f:e6:c4:e8:d1 is duplicate on halls-banta-hepburn
Jun  5 08:30:45 dhcp-1 dhcpd: DHCPREQUEST for 10.10.2.143 (10.234.220.191) from fc:0f:e6:c4:e8:d1 via 10.10.2.253: lease owned by peer
Jun  5 08:30:45 dhcp-1 dhcpd: uid lease 10.10.2.161 for client fc:0f:e6:c4:e8:d1 is duplicate on halls-banta-hepburn
Jun  5 08:30:45 dhcp-1 dhcpd: DHCPREQUEST for 10.10.2.143 (10.234.220.191) from fc:0f:e6:c4:e8:d1 via 10.10.2.252: lease owned by peer
Jun  5 08:30:45 dhcp-2 dhcpd: DHCPREQUEST for 10.10.2.143 (10.234.220.191) from fc:0f:e6:c4:e8:d1 via 10.10.2.253
Jun  5 08:30:45 dhcp-2 dhcpd: DHCPACK on 10.10.2.143 ends 2014/06/05:13:00:45 to fc:0f:e6:c4:e8:d1 via 10.10.2.253
Jun  5 08:30:45 dhcp-2 dhcpd: DHCPREQUEST for 10.10.2.143 (10.234.220.191) from fc:0f:e6:c4:e8:d1 via 10.10.2.252
Jun  5 08:30:45 dhcp-2 dhcpd: DHCPACK on 10.10.2.143 ends 2014/06/05:13:00:45 to fc:0f:e6:c4:e8:d1 via 10.10.2.252
Jun  5 08:45:46 dhcp-2 dhcpd: DHCPREQUEST for 10.10.2.143 from fc:0f:e6:c4:e8:d1 via eth0
Jun  5 08:45:46 dhcp-2 dhcpd: DHCPACK on 10.10.2.143 ends 2014/06/05:20:45:46 to fc:0f:e6:c4:e8:d1 via eth0
Jun  5 08:58:03 dhcp-2 dhcpd: DHCPRELEASE of 10.10.2.143 from fc:0f:e6:c4:e8:d1 via eth0 (found)
Jun  5 11:08:15 dhcp-1 dhcpd: DHCPDISCOVER from fc:0f:e6:c4:e8:d1 via 10.10.2.253: load balance to peer dhcp
Jun  5 11:08:15 dhcp-1 dhcpd: DHCPDISCOVER from fc:0f:e6:c4:e8:d1 via 10.10.2.252: load balance to peer dhcp
Jun  5 11:08:15 dhcp-2 dhcpd: DHCPDISCOVER from fc:0f:e6:c4:e8:d1 via 10.10.2.253
Jun  5 11:08:16 dhcp-2 dhcpd: DHCPOFFER on 10.10.2.137 ends 2014/06/05:15:10:15 to fc:0f:e6:c4:e8:d1 via 10.10.2.253
Jun  5 11:08:16 dhcp-1 dhcpd: uid lease 10.10.2.143 for client fc:0f:e6:c4:e8:d1 is duplicate on halls-banta-hepburn
Jun  5 11:08:16 dhcp-1 dhcpd: DHCPREQUEST for 10.10.2.137 (10.234.220.191) from fc:0f:e6:c4:e8:d1 via 10.10.2.252: lease owned by peer
Jun  5 11:08:16 dhcp-1 dhcpd: uid lease 10.10.2.143 for client fc:0f:e6:c4:e8:d1 is duplicate on halls-banta-hepburn
Jun  5 11:08:16 dhcp-1 dhcpd: DHCPREQUEST for 10.10.2.137 (10.234.220.191) from fc:0f:e6:c4:e8:d1 via 10.10.2.253: lease owned by peer
Jun  5 11:08:16 dhcp-2 dhcpd: DHCPREQUEST for 10.10.2.137 (10.234.220.191) from fc:0f:e6:c4:e8:d1 via 10.10.2.253
Jun  5 11:08:16 dhcp-2 dhcpd: DHCPACK on 10.10.2.137 ends 2014/06/05:15:38:16 to fc:0f:e6:c4:e8:d1 via 10.10.2.253
Jun  5 11:08:16 dhcp-2 dhcpd: DHCPREQUEST for 10.10.2.137 (10.234.220.191) from fc:0f:e6:c4:e8:d1 via 10.10.2.252
Jun  5 11:08:16 dhcp-2 dhcpd: DHCPACK on 10.10.2.137 ends 2014/06/05:15:38:16 to fc:0f:e6:c4:e8:d1 via 10.10.2.252



Thanks!

Sue